Urry D.W. (Ed.) What Sustains Life? : Consilient Mechanisms for Protein-Based Machines and Materials

Подождите немного. Документ загружается.

Advanced Materials for the Future:

Protein-based Materials with Potential

to Sustain Individual Health and

Societal Development

The industrial revolution of the Nineteenth

Century was born of the water-to-steam phase

transition. As implicit in the last three chapters

and explicit in the Epilogue, biology was born of

the inverse temperature transition. As argued in

this chapter, the advanced biomaterials renais-

sance of the Twenty-first Century will also have

been born of the inverse temperature transition.

9.1 Introduction

9.1.1 The Appeal of New Discoveries

and Their Utilization

"Nothing is more agreeable to men (those)

devoted to a scientific career than to increase

the number of discoveries, but when the result

of their observation is demonstrated by practi-

cal utility their joy is complete."^ Louis Pasteur

penned these words a century and a half ago.

So appropriate is this perspective today to

those "devoted to a scientific career" that one

might only add that further joy comes when

"practical utility" enables further discoveries by

providing the necessary funding. It is in this

vein, fueled by the firm belief in the remark-

able range of applications of protein-based

machines and materials, that we have efforts

underway to develop uses. The potential appli-

cations promise to help society attain a number

of its goals, such as improving health and

quality of life, reducing cost of health care, alle-

viating addiction, and relieving environmental

pollution.

9.1.2 The Unrivaled Opportunity to

Achieve Utility of Advanced

Biomaterials

In Chapter 5, based on an inverse temperature

transition due to hydrophobic association in

water, a set of Axioms were derived from the

phenomenological demonstration that de novo

designed model proteins could efficiently inter-

convert the set of energies interconverted by

living organisms. Then there followed a series

of experimental results and analyses that

defined the comprehensive hydrophobic effect.

The operative component of the comprehen-

sive hydrophobic effect arises from the compe-

tition between charged and oil-like groups. TTiis

was shown to result in a previously unknown

repulsive force embodied within an interaction

energy called an apolar-polar repulsive free

energy of hydration, AGap. During function,

AGap works in conjunction with elastic force

development by the restriction of internal

chain dynamics. These have been called the

hydrophobic and elastic consilient mechanisms.

In Chapters 6,7, and 8, these consilient mecha-

nisms were demonstrated to be fundamental

to understanding the functions of biology's

proteins.

If our advances built over the last three

decades and culminating in the new analyses

and data in Chapter 5 are sound, then we are at

a historic moment in biomaterials development.

This moment opens the door to an unprece-

dented future for biomaterials. The opportunity

is founded on an understanding of the forces

455

456 9. Advanced Materials for the Future

responsible for protein function, demonstrated

in part in the new structure-function analyses in

Chapter 8 and culminating in the Epilogue as

constituting the "vital force" of biology. The

practical utilization of the hydrophobic and con-

silient mechanisms couples with the capacity for

biological production of designed protein-based

polymers of almost unlimited diversity of com-

position and size.

Finally, for medical applications, the extraor-

dinary biocompatibility of these elastic protein-

based materials, we believe, arises from the

specific means whereby these elastic protein-

based polymers exhibit their motion. Being

composed of repeating peptide sequences that

order into regular, nonrandom, dynamic struc-

tures,

these elastic protein-based polymers

exhibit mechanical resonances that present bar-

riers to the approach of antibodies as required

to be identified as foreign. In addition, we also

believe that these mechanical resonances result

in extraordinary absorption properties in the

acoustic frequency range.

9.1.3 The Relationship Between Basic

Science and Its AppUcations

9,13,1 Our Perspective for

Protein-based Polymers

Chapter 5 presents in one place, more exten-

sively and in a more advanced state than pre-

viously, the decades long development of the

comprehensive hydrophobic effect, the under-

pinnings of the hydrophobic consilient mecha-

nism, whereby the control of hydrophobic

association commands diverse energy conver-

sion functions of protein-based polymers.

Chapters 7 and 8 demonstrate the comprehen-

sive hydrophobic effect and its interlinked

elastic consiUent mechanism to be vital aspects

of protein function and dysfunction in biology.

In the present chapter, we utilize this developed

capacity to engineer protein-based polymers to

demonstrate a few of an extraordinary range of

appUcations.

Design of function comes through control of

the Gibbs free energy of hydrophobic associa-

tion,

AGHA-With

regard to medical appUcations,

protein, biology's own workhorse polymer of

choice, provides the most congruent means

with which to restore function and defeat

disease. As noted in section 5.2.5, the nature of

their elasticity and resulting biocompatibility

and their never-ending design potential makes

the family of elastic protein-based polymers,

developed here, the pre-eminent choice of

materials for medical applications.

With regard to nonmedical applications, the

entirely unique opportunity to specify compo-

sition and diverse sequence, so precisely, pro-

vides a profusion of polymers with properties

that bring to the nonmedical world all of the

specificity and sensitivity of which biology's

protein is renown. To the best of our under-

standing, the properties include a remarkable

and unique acoustic absorption capacity. Also

unconstrained by the parameters of living

organisms, but armed with the engineering

capacity provided by knowledge of the hydro-

phobic and elastic consilient mechanisms,

designed protein-based polymers give rise to

materials unknown to living organisms. We now

look toward enumerable challenges where

defined needs stimulate designs of protein-

based polymers to fulfill those needs.

9,1,3,2 Pasteur on the Relationship

Between the Basic and Applied Sciences

Before proceeding to the range and significance

of problems addressable with the diverse prop-

erties of protein-based materials, the relation-

ship between basic research and its derivative

applications warrants further consideration.

Again we turn to Pasteur: 'Wo, a thousand times

no;

there does not exist a category of science to

which one can give the name applied science.

There are science and the applications of science,

bound together as the fruit to the tree which

bears

it,''^

Pasteur knew the relationship well.

He made major advances in the basic sciences,

for example, in crystal structure and optical

activity and in advancing the germ theory that

put to rest the unproductive concept of sponta-

neous generation of living organisms. He also

made advances resulting in more familiar appli-

cations. He developed the process now known

as pasteurization that saved the wine, vinegar,

and beer industries of France but that we daily

identify with pasteurized milk products; he

solved a threat to the silk industry by alleviat-

9.1 Introduction

457

ing diseases of the silkworm, and he developed

an understanding and successful treatment of

rabies. All of this came about by singular

advances that were often in severe conflict with

the prevailing thought of his day.

9.1.3.3 Cyclical Enabling: The

Relationship Between Science and the

Applications of Science

Development of applications proceeds effec-

tively when a scientific foundation is employed.

On the other hand, development of the scien-

tific foundation becomes empowered by

society's need to solve current problems. This is

what is intended by the term cyclical enabling.

Building upon Pasteur's words, it might further

be said that. To separate the development of

science from the development of applications

would be to separate the growing fruit from its

tree; the immature fruit wither and waste and

yield no new trees, and the barren tree too soon

dies

The development of thermodynamics is one

example of this interdependence. Thermody-

namics, a paradigm of basic science, grew from

society's appetite for better steam engines with

which to relieve humans and horses of mechan-

ical work. Of particular relevance here, the

discipUne of thermodynamics provides the

scientific foundation for energy conversion by

protein machines. Chapter 5 demonstrates this

with consideration of the thermodynamics of

hydrophobic association in model proteins. A

thermodynamic understanding of energy con-

version provides the scientific foundation for

the most effective development of the applica-

tions considered below. The Epilogue inte-

grates the keystone of thermodynamics, the

second law, into the unique adherence by bio-

logical systems.

9.1.3.4 Specific Enablers of the

Development of Elastic

Protein-based Polymers

In general, development of the scientific foun-

dation for protein-based polymers began in an

academic setting and continued very effectively

in a company setting. The primary funding

impetus (the enabler) for the development of

elastic protein-based polymers has been grants

and contracts from the Office of Naval

Research, covering nearly two decades of

support in academic institutions and in a

company setting, also with support from the

Naval Medical Research and Development

Command in the company setting. Develop-

ment of a scientific foundation for elastic

protein-based polymers occurred in order to

provide the most effective approach to devel-

opment of materials applications. The second

most prominent level of support has come from

the National Institutes of Health, primarily in

terms of Small Business Innovation Research

contracts (SBIRs), The SBIRs decidedly focus

on appHcations and draw from the foundations

of the science of the elastic-contractile model

proteins presented in Chapter 5.

The primary advances toward appHcations

occurred in a company setting. In fact, even

much of the foundation of the relevant under-

lying science occurred in the company set-

ting. For example, fundamental knowledge of

hydrophobic association in proteins, of protein

elasticity, of mechanical (e.g., acoustical) reso-

nances, and so forth resulted from progress

made in the company setting. These contribu-

tions to the foundation of the science obviously

relate to the solution of practical problems—

developing rules for correctly folding micro-

bially prepared protein of higher organisms,

designing a new class of sound-absorbing

materials, and developing nanomachines and

nanosensors. Consistent with the Pasteur per-

spective, progress toward applications for

elastic and plastic protein-based polymers

resulted from the cyclical enabling noted

above.

9.1.4 The Incomparable Potential of

Protein-based Polymers

9.1.4.1 General Advantages of

Protein-based Polymers

Many extraordinary advantages of protein-

based polymers exist. Some of the advantages

are briefly listed.

Two modes of synthesis: chemical and

biological: Chemical synthesis allows for rela-

tively rapid screening of physical properties of

hundreds of protein-based polymer composi-

458

9. Advanced Materials for the Future

tions as long as they are not too complex. Even

so,

chemical synthesis has disadvantages of

racemization, of side reactions on protection/

deprotection of functional side chains, of

random incorporation of guest pentamer, of a

distribution of chain lengths, and so forth, all of

which limit quantification of engineering prin-

ciples.

On identification of chemically synthe-

sized model protein compositions of particular

interest, the slower process of recombinant

DNA technology for gene construction and

development of an effective expression system

ultimately provides for rapid, large-scale pro-

duction and other advantages discussed below.

Of importance in the most accurate develop-

ment of protein-based polymers as biomateri-

als,

however, will be to obtain the most accurate

set of controlling interaction energies to arrive

at the desired level of reUance on derived engi-

neering principles.

Diversity of monomers: The biosynthesis

of natural proteins utilizes 20 different

monomeric units, and chemical and enzy-

matic post-translational modifications provide

further diversity of sequence. As discussed in

Chapter 4 and noted below, the availabiUty of

20 different monomers results in an inordinate

number of different protein sequences, even for

a small 100 residue protein, that is,

10^^^.

Precise control of the sequence of amino

acid residues'. Any protein-based polymer

sequence utilizing the 20 naturally occurring

monomers can be specified using recombinant

DNA technology. This allows for equivalent

ease of production of diverse protein-based

polymer sequences, many of which would

otherwise be quite difficult or essentially im-

possible to prepare due to problems of chemi-

cal synthesis and unfavorable energetics in the

final polymer.

Exact control of stereochemistry. Control

of stereochemistry, for example, use of a single

optical isomer as occurs in biology, is essential

for control of physical properties resulting in

unique structures and more precise function.

The occurrence of some racemization is

unavoidable during chemical synthesis of long

protein-based polymers. Some inclusion of D-

amino acid residues, rather than having all L-

amino acid residues (see Figure 3.3C) as occurs

in biology, is unavoidable in chemical synthesis.

Even an amount of racemization as small as

can critically limit desirable properties in these

nonrandom elastic polymers. For example, lack

of rigorous exclusion of racemization during

chemical synthesis of poly(GVGVP) can cause

the critical onset temperature for the inverse

temperature transition for hydrophobic associ-

ation (Tt) to be raised by 15°C from 25° to 40°C.

As explained in Chapter 5, control of Tj is

central to controlling function.

Precise chain lengths: The gene encoding

for a protein-based polymer occurs, generally,

with a single chain length, and the complete

range of chain lengths, arising from multiples of

a basic repeating gene sequence, are possible in

Escherichia coli, resulting in as many as 4,000

amino acid residues and even more than 1

milHon residues in animals. This allows for fine-

tuning of desirable properties and access to

new capabilities. Several processes occur that

can defeat this possibility of all polymer chains

being of the same chain length. Deletion of

gene sequences can occur under certain cir-

cumstances. The growing protein chain can fall

off the ribosome before completion of transla-

tion, and the expressed protein can be sub-

jected to proteolytic degradation. All of these

complications, however, are generally avoid-

able,

and precise chain lengths are routinely

obtained.

6. Capacity to introduce natural bioactive

peptide sequences (protein mimicry): With an

adequate understanding of protein engineer-

ing, there exists an essentially unlimited capac-

ity to mimic chosen elements of more complex

proteins in terms of both structure and func-

tion. Specific biologically active sequences can

be introduced with ease. Examples are sites at

which selective enzymes can catalyze a desired

reaction, sequences for selective cell attach-

ment, selective attachment to diseased cells for

drug delivery, and so forth.

Circumstances of protein function to

guide approach and analyses: It is possible to

consider functional proteins, for example, with

their natural prosthetic groups and cofactors, to

suggest important variables that relate to func-

tion, and these become tools with which to

achieve protein engineering (see Tables 5.1 and

9.1 Introduction 459

5.2). For example, prosthetic groups and cofac-

tors can be attached to model proteins, and the

role of each as regards function can be quanti-

fied and utilized.

8. Properties and uses beyond those of

known proteins: Once the rules for protein

engineering have been established, protein-

based polymers can be designed with proper-

ties and functions that go beyond what

evolution has called upon proteins to do. For

example, there are model proteins for con-

trolled release of new pharmaceuticals, and

programmable, biodegradable thermoplastic

protein-based polymers that melt for easy

molding or extruding at 150°C, with decompo-

sition not occurring until 250°C.

9. Low cost of bioproduction: As the

designed protein-based polymer becomes more

complex, the cost advantages of bioproduction

become greater. The production of protein-

based polymers by means of recombinant DNA

technology has the potential for at least a

10,000-fold decrease in cost from that of chem-

ical synthesis. It is believed that the cost of

protein-based polymers has the potential to be

competitive with the cost of petroleum-based

polymers, thus relieving, in part, society's

dependence on limited oil reserves. Further-

more, it costs a living organism no more energy

to produce a more efficient protein-based

machine than an inefficient one of the same

size.

10.

Produced from renewable resources:

Living organisms—E. coli, yeast, plants, and

animals—can be designed to produce protein-

based polymers. Protein-based polymers can be

produced with renewable resources. They can

be prepared without resorting to toxic and

noxious chemicals, and they can be pro-

grammed for a desired biodegradation. For

example, they can mean food for the fishes

rather than death to marine life, as occurs with

present plastics. Thus, protein-based polymers

can be environmentally friendly for their com-

plete life cycle, from production to disposal.

11.

Axioms for protein-based polymer engi-

neering: The phenomenology of protein-based

polymer function, categorized in terms of free

energy transduction, is given as a set of five

Axioms in Chapter 5 (see section 5.6.3). These

five Axioms provide the basis for diverse, but

qualitative, designs of polymers capable of

exhibiting inverse temperature transitions.

12.

Quantitative design principles available

for protein-based polymers: The comprehensive

hydrophobic effect, developed in Chapter 5,

provides principles for the quantitative design

of protein-based polymers. The dominant

underlying energetics are embodied in the

Gibbs free energy for hydrophobic association,

AGHA,

as modified by the newly described

Gibbs free energy for an apolar-polar repulsive

free energy of hydration, AGap.

13.

Availability of the most efficient mecha-

nism for achieving function in an aqueous

environment: Comparison of the electrosta-

tic charge-charge repulsion mechanism for

chemo-mechanical transduction with that of

the apolar-polar repulsive free energy of

hydration, AGap, shows the latter to be more

than an order of magnitude more efficient. This

becomes particularly relevant to biomedical

applications of controlled release as required in

drug delivery, but also whenever a sensitive and

responsive (smart) biomaterial is desired.

14.

Remarkable biocompatibility of elastic

protein-based polymers: When considering

medical apphcations of these biomaterials,

utihty depends on biocompatibility. After all,

foreign proteins are generally antigenic and

elicit production of antibodies. This is the basis

for many vaccines. How then can one propose

protein as a biomaterial? The most direct

answer is that many biocompatibility studies

have been carried out on a number of compo-

sitions of elastic protein-based polymers, and

they have been found to exhibit extraordinary

biocompatibility. In fact, very pure preparations

of (GVGVP)n, or equivalently (VPGVG)n,

appear to be entirely ignored by the host. This

we believe is due to the nature of the elasticity.

In our view, ideal or entropic elasticity exhib-

ited by poly(VPGVG) results from the fact that

the repeating conformational unit, (VPGVG),

exhibits mechanical resonances. These are

motions that occur with frequencies localized

near

MHz and

kHz. Such low-frequency

motions greatly stabilize the structure. Further-

more, the requirement to stop these motions, as

needed to identify an epitope for the develop-

460 9. Advanced Materials for the Future

ment of antibodies to the sequence, presents a

barrier to the approach and identification of the

elastic protein-based polymer as foreign.

15.

In vivo breakdown products: Other poly-

meric biomaterials may also be composed

of natural products, such as polyesters like

poly(glycolic acid) and poly (lactic acid). When

these polymeric biomaterials degrade to the

naturally occurring monomers of glycolic acid

and lactic acid, however, the monomeric car-

boxylic acid ionizes to release acid, H^. The

decreased pH can be a significant irritant to the

tissues. On the other hand, when protein-based

polymers undergo biodegradation, naturally

occurring zwitterionic amino acids are released

without such an effect on the pH and its

ramifications.

When seeking an optimal biomaterial, the

preference is for complete absence of toxicity

on placement in the host. With such a totally

innocuous elastic protein-based biomaterial,

biologically active sequences can be readily

included within the polymer, and the host tissue

can react to the biologically active sequence

without being overwhelmed by unwanted reac-

tions.

Thus, because of the high level of bio-

compatibility, there exists the capacity to elicit

diverse and desired tissue responses.

Hopefully, the foregoing brief Usts provides

some insight into the potential of protein-based

polymers in the marketplace. There simply are

no comparable soft materials for medical appli-

cations. Certain of the above-listed advantages

are discussed in more detail immediately below

and throughout this chapter.

9.1.4.2 A Near-infinite Number of

Different Polymer Compositions

There are 20 different naturally occurring

amino acid residues, and each position in a

biosynthesized protein-based polymer can

contain any one of the 20 amino acids. As con-

sidered in Chapter 4, this means even for a

small 100 residue protein-based polymer that

there are

(20)^^^

10^^^

different sequences pos-

sible.

The size of this number is hard to com-

prehend. For example, if the mass of the known

universe were composed of nothing but 100

residue protein-based polymers and if there

were only one molecule of each possible

sequence, the likelihood of the occurrence of a

specific sequence would yet remain extremely

remote.

Capitalizing on the potential of protein-

based polymers with such a near-infinite

number of sequences requires an understand-

ing of the basis for function. The hydrophobic

and elastic consilient mechanisms for design of

protein-based polymer structure and function,

the knowledge for which is developed primar-

ily in Chapter 5, enable utilization of the

extraordinary potential of these incomparable

polymers. Humans utilize fewer than 50,000

dif-

ferent proteins, and, as learned from sequence

data of the human genome and those of lower

and less complex animals, plants, and organ-

isms,

a surprisingly hmited number of the fewer

than 50,000 protein sequences are unique to

humans. Accordingly, the potential for materi-

als that go beyond those known in biology rings

clear.

Obviously, the appUcations of protein-based

polymers are innumerable. The appUcations

discussed in this chapter represent but a few of

very very many, and they are at different stages

of development.

9.1.4.3 Available Fundamental Design

Principles Yield Effective Products

The five phenomenological Axioms, knowledge

of the underlying physical basis and thermody-

namic formaUsm in terms of the Gibbs free

energy of hydrophobic association,

AGHA,

provide a foundation for fundamental design

principles. The efficiency rating, ecM» as pre-

sented in section 5.9.3, recognizes

AGHA

as a

maximal energy output for a given design based

on the consiUent mechanism, that is, the com-

prehensive hydrophobic effect. Given a defined

energy source, which could be a drug, for

example, the issue becomes one of designing

the preferred protein-based polymer that

would most accurately target the desired

outcome. In particular, the drug can be the

energy input for assembly of the drug delivery

vehicle that released drug in the desired

manner as the energy output. In every case with

the hydrophobic and elastic consilient mecha-

nisms, the interlinked physical processes that

achieve the energy conversion are a change in

9.1 Introduction 461

hydrophobic association in conjunction with a

near-ideal polymer elasticity.

9.1.4.4 De novo Design of a Material for

the Intended Application

From the outset, our approach has been to

design materials for an intended function.

In particular, each new energy conversion

described in Chapter 5 was achieved by design

of a new functionality utilizing the perspective

of a common underlying hydrophobic con-

sihent mechanism. Jacob Bronowski^ antici-

pated such an approach three decades ago in

his book Ascent of Man, with the perspective

that, "In effect, the modern problem is no longer

to design a structure from the materials (avail-

able) but to design materials for a structure.''

Knowledge of the Axioms and the principles

underlying the comprehensive hydrophobic

effect, based at the molecular level on the

change in free energy of hydrophobic associa-

tion, makes it possible to "design materials for

a structure." Of course, by structure we gener-

ally mean a unique protein sequence, also

referred to as primary structure or in a more

general way as composition. By materials for a

structure, Bronowski meant a composition

designed for a specific function. This is to be dis-

tinguished from taking a given composition and

coercing a function for which it is not sequence

optimized.

An example of

"^<9

design a structure from the

materials'' would be to achieve the function of

a chemo-mechanical engine using the initial

available model protein composition poly

(GVGVP), cross-linking it by y-irradiation, and

employing the chemical energy of adding

salt(NaCl) to drive contraction.^ In this case,

AGHA[poly(GVGVP)(0.1 N ^ 1.0 N NaCl)] is

-0.5kcal/mole-pentamer/mole-NaCl.

On the other hand, to "design materials for a

structure," in this case a better salt (NaCl)-

driven chemo-mechanical engine, would be to

design a protein-based polymer with a few

glutamic acid residues per 100 residues, for

example, poly[4(GVGVP),(GEGVP)]. As

listed in Table 5.4, for the newly designed struc-

ture over its most responsive range to NaCl

from 0.15 N to 0.25 N NaCl, AGeAlpoly

[0.8(GVGVP),0.2(GE-GVP)]}, is -9.4kcal/

mole-pentamer/mole-NaCl; this gives an

improvement for the most effective ranges of

9.35/0.5. Thus, "to design materials for a struc-

ture'' as was done by designing the polymer

poly[4(GVGVP),(GEGVP)], to be an NaCl-

driven chemo-mechanical engine, was to design

a chemo-mechanical engine with an effective-

ness of energy conversion improved by nearly

a factor of 20 when functioning in its most

effective concentration range. Clearly, the

modern problem is "to design materials for a

structure'' and the means to do so comes from

an understanding of the hydrophobic consilient

mechanism's comprehensive hydrophobic ef-

fect, as developed in Chapter 5.

Thus,

poly(GVGVP) was a structure avail-

able from the mammalian elastic fiber. Adding

a carboxyl function resulted in a structure that

was not previously known, and the resulting

design gave rise to a structure that could do 20

times more work for the same chemical energy

input. This exemplifies the modern approach of

designing a material specifically for a chemo-

mechanical structure. Contemplation of any

application of these protein-based polymers

best proceeds with understanding of the under-

lying physical process in order to achieve the

most effective outcome. Most functions can be

analyzed in terms of the efficiency of energy

conversion. This is most readily appreciated for

the controlled release of pharmaceuticals, that

is,

for drug delivery.

9.1.5 Potential of Protein-based

Materials to Improve Health and

Decrease Health Care Costs

Health care costs in the United States exceed a

staggering trilUon dollars per year. Low back

pain, urinary incontinence, pressure ulcers (e.g.,

bed sores), and cardiovascular disease are

major contributors to decreased quality of life

and increased health care

costs.

Apphcations of

protein-based materials, briefly noted in this

section but discussed more extensively below,

have the potential to improve quality of life

while lowering health care costs for these and

additional medical problems. To provide a his-

torical backdrop and a record of the develop-

ment of applications. Table 9.1 provides the set

of patents resulting from our research efforts.

462

Advanced Materials

for the

Future

TABLE

9.1. Bioelastics Research, Ltd., patent Ust.

Inventors: D.W. Urry

and K.

Okamoto

Title:

Synthetic Elastomeric Insoluble Cross-Linked Polypentapeptide

Country

USA

Canada

Patent

No.

4,132,746

1103238

Date Filed

07/09/76

02/26/79

Inventors: D.W. Urry

and K.

Okamoto

Title:

Synthetic Elastomeric Insoluble Cross-Linked Polypentapeptide

Country

USA

Patent

No.

4,187,852

Inventor: D.W. Urry

Title:

Elastomeric Composite Material Comprising

Polypeptide

Country Patent

No.

USA 4,474,851

Date Filed

08/14/78

Date Filed

10/02/81

Date Issued

01/02/79

06/16/81

Date Issued

02/12/80

Date Issued

10/02/84

Inventor: D.W. Urry

Title:

Elastomeric Composite Material Comprising

Polypentapeptide Having

Amino Acid

Opposite

Chirality

Postion Three

Country Patent No. Date Filed Date Issued

USA 4,500,700 12/23/82 02/19/85

Inventor: D.W. Urry

Title:

Enzymatically Cross-Linked Bioelastomers

Country Patent

No.

USA 4,589,882

Date Filed

09/19/83

6. Inventors: D.W. Urry

and

R.M. Senior

Title:

Stimulation

Chemotaxis

Chemotactic Peptides (Hexapeptide)

Country Patent No. Date Filed

USA 4,605,413 09/19/83

Inventors: D.W. Urry

and

M.M. Long

Title:

Stimulation

Chemotaxis

Chemotactic Peptides (Nonapeptide)

Country Patent No. Date Filed

USA 4,693,718 10/31/85

Date Issued

05/20/86

Date Issued

08/12/86

Date Issued

09/15/87

8. Inventors: D.W. Urry

and

K.U.M. Prasad

Title:

Temperature Correlated Force

and

Structure Development

Elastin Polytetrapeptides

Polypentapeptides

Country Patent No. Date Filed Date Issued

USA 4,783,523 08/27/86 11/08/88

Europe

0321496 03/30/94

Japan 2726420 08/27/87 12/05/97

9. Inventors: D.W. Urry

and

K.U.M. Prasad

Title:

Segmented Polypeptide Bioelastomers

Modulate Elastic Modulus

Country Patent No. Date Filed Date Issued

USA 4,870,055 04/08/88 09/26/89

Japan 2085090 04/17/87 08/23/96

10.

Inventor: D.W. Urry

Title:

Bioelastomer Containing Tetra/ Pentapeptide Units

Country Patent No. Date Filed Date Issued

USA 4,898,926 06/15/87 02/06/90

Europe 06/13/88

11.

Inventor: D.W. Urry

Title:

Reversible Mechanochemical Engines Comprised

Bioelastomers Capable

Modulable Inverse

Temperature Transitions

for the

Interconversion

Chemical

and

Mechanical Work

Country Patent No. Date Filed Date Issued

USA 5,032,271 06/15/87 07/16/91

Europe

0425491 06/13/88 07/20/94

9.1 Introduction

463

TABLE

9.1.

Continued

12.

Inventor: D.W. Urry

Title:

Reversible Mechanochemical Engines Comprised of Bioelastomers Capable of Modulable Inverse

Temperature Transitions for the Interconversion of Chemical and Mechanical Work

Country Patent No. Date Filed Date Issued

USA 5,085,055 04/30/91 02/04/92

13.

Inventor: D.W. Urry

Title:

Reversible Mechanochemical Engines Comprised of Bioelastomers Capable of Modulable Inverse

Temperature Transitions for the Interconversion of Chemical and Mechanical Work

Country Patent No. Date Filed Date Issued

USA 5,255,518 12/24/91 10/26/93

14.

Inventors: D.W. Urry and M.M. Long

Title:

Stimulation of Chemotaxis by Chemotactic Peptides

Country Patent No. Date Filed Date Issued

USA 4,976,734 09/19/87 12/11/90

Europe EP 0366777 06/13/88 07/20/94

15.

Inventor: D.W. Urry

Title:

Bioelastomeric Materials Suitable for Burn Areas or the Protection of Wound Repair Sites from the

Occurrence of Adhesions

Country Patent No. Date Filed Date Issued

USA 5,250,516 04/21/88 10/05/93

Europe EP 0365655 09/21/94

Japan 2820750 04/14/89 08/28/98

16.

Inventor: D.W. Urry

Title:

Elastomeric Polypeptides as Vascular Prosthetic Materials

Country Patent No. Date Filed

USA 5,336,256 04/22/88

Europe EP 0365654

Japan 2115962 04/14/89

17.

Inventor: D.W. Urry

Title:

Polynonapeptide Bioelastomers Having an Increased Elastic Modulus

Country Patent No. Date Filed

USA 5,064,430 02/23/89

18.

Inventor: D.W Urry

Title:

Polymers Capable of Baromechanical and Barochemical Transduction

Country Patent No. Date Filed

USA 5,226,292 04/22/91

19.

Inventor: D.W. Urry

Title:

Superabsorbent Materials and Uses Thereof

Country Patent No. Date Filed

USA 5,393,602 04/19/91

Europe EP 0580811 03/10/93

Japan 4-510189 03/10/92

20.

Inventor: D.W. Urry

Title:

Superabsorbent Materials and Uses Thereof

Country Patent No. Date Filed

USA 5,520,672 02/06/95

21.

Inventor: D.W. Urry

Title:

Elastomeric Polypeptide Matrices for Preventing Adhesion of Biological Materials

Country Patent No. Date Filed

USA 5,527,610 05/20/94

Japan 05/20/95

22.

Inventor: D.W. Urry

Title:

Elastomeric Polypeptide Matrices for Preventing Adhesion of Biological Materials

Country Patent No. Date Filed

USA 5,519,004 06/07/95

Date Issued

08/09/94

01/12/94

12/06/96

Date Issued

11/12/91

Date Issued

07/13/93

Date Issued

02/28/95

08/04/99

07/26/02

Date Issued

05/28/96

Date Issued

06/18/96

Date Issued

05/21/96

464 9. Advanced Materials for the Future

TABLE

9.1.

Continued

23.

Inventor: D.W. Urry

Title:

Bioelastomeric Drug Delivery System

Country Patent No. Date Filed

USA 6,328,996 Bl 10/03/94

Europe EP 0449592

Japan 1994740

24.

Inventors: D.W. Urry, P. Shewry, and U. Prasad Kari

Title:

Bioelastomers Suitable as Food Product Additives

Country Patent No. Date Filed

USA 5,972,406 10/13/95

Europe 96912815.6 04/15/96

Japan 8-531270 04/23/2002

25.

Inventors: D.W. Urry, H. Daniell, D. McPherson, and J. Xu

Title:

Hyperexpression of Bioelastomeric Polypeptides

Country Patent No. Date Filed

USA 6,004,782 10/13/95

26.

Inventor: D.W. Urry

Title:

Bioelastomers Suitable as Food Product Additives

Country Patent No. Date Filed

USA 5,900,405 06/07/95

Europe 0830509 06/07/96

Japan 9-519202 08/06/97

27.

Inventors: D.W. Urry, D. McPherson, and J. Xu

Title:

A Simple Method for the Purification of a Bioelastic Polymer

Country Patent No. Date Filed

USA 5,854,387 10/13/95

Europe 96912768.7 04/15/96

Japan 8-531261 04/16/2002

28.

Inventor: D.W. Urry

Title:

Acoustic Absorption Polymers and Their Methods of Use

Country Patent No. Date Filed

USA 09,746,371 12/20/00

Europe PCT/US 00/34658 7/22/02

29.

Inventor: D.W. Urry

Title:

Bioelastomer Nanomachines and Biosensors (NEMS)

Country Patent No. Date Filed

USA 09/888,260 06/21/01

Europe PCT/USOl/20045 06/21/01

30.

Inventor: D.W. Urry

Title:

Injectable Implants for Tissue Augmentation And Generation

Country Patent No. Date Filed

USA 09/837,969 04/18/01

Canada 2,319,558 02/26/99

31.

Inventor: D.W. Urry

Title:

Injectable Implants for Tissue Augmentation And Generation

Country Patent No. Date Filed

USA 09/841,321 04/23/01

Europe 99908590.5 02/26/99

Canada 2,319,558 02/26/99

Japan 533072/2000 02/26/99

32.

Inventors: D.W. Urry, P Glazer, and T.M. Parker

Title:

Injectable Implants for Tissue Augmentation And Generation

Patent No. Date Filed

6,533,819 Bl 04/23/01

Country

USA

Date Issued

12/11/01

11/30/94

11/22/95

Date Issued

10/26/99

Pending

Date Issued

12/21/99

Date Issued

05/04/99

03/25/98

Pending

Date Issued

12/29/98

Pending

Date Issued

Pending

Date Issued

Pending

Date Issued

In Allowance

Pending

Date Issued

Pending

Date Issued

03/18/03