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1.
Chembiochem ; 25(8): e202300835, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38390634

RESUMO

Self-assembled hydrogels, fabricated through diverse non-covalent interactions, have been extensively studied in regenerative medicines. Inspired from bioactive functional motifs of ECM protein, short peptide sequences have shown remarkable abilities to replicate the intrinsic features of the natural extracellular milieu. In this direction, we have fabricated two short hydrophobic bioactive sequences derived from the laminin protein i. e., IKVAV and YIGSR. Based on the substantial hydrophobicity of these peptides, we selected a co-solvent approach as a suitable gelation technique that included different concentrations of DMSO as an organic phase along with an aqueous solution containing 0.1 % TFA. These hydrophobic laminin-based bioactive peptides with limited solubility in aqueous physiological environment showed significantly enhanced solubility with higher DMSO content in water. The enhanced solubility resulted in extensive intermolecular interactions that led to the formation of hydrogels with a higher-order entangled network along with improved mechanical properties. Interestingly, by simply modulating DMSO content, highly tunable gels were accessed in the same gelator domain that displayed differential physicochemical properties. Further, the cellular studies substantiated the potential of these laminin-derived hydrogels in enhancing cell-matrix interactions, thereby reinforcing their applications in tissue engineering.


Assuntos
Dimetil Sulfóxido , Hidrogéis , Hidrogéis/química , Solventes , Peptídeos/química , Laminina/química
2.
Biomacromolecules ; 25(6): 3271-3287, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38712837

RESUMO

Tuning self-assembling pathways by implementing different external stimuli has been extensively studied, owing to their effective control over structural and mechanical properties. Consequently, multicomponent peptide hydrogels with high structural tunability and stimuli responsiveness are crucial in dictating cellular behavior. Herein, we have implemented both coassembly approach and pathway-dependent self-assembly to design nonequilibrium nanostructures to understand the thermodynamic and kinetic aspects of peptide self-assembly toward controlling cellular response. Our system involved an ultrashort peptide gelator and a hydrophilic surfactant which coassembled through different pathways, i.e., heat-cool and sonication methods with variable energy input. Interestingly, it was possible to access diverse structural and mechanical properties at the nanoscale in a single coassembled system. Further, the hydrophilic surfactant provided additional surface functionalities, thus creating an efficient hydrophilic matrix for cellular interaction. Such diverse functionalities in a single coassembled system could lead to the development of advanced scaffolds, with applications in various biomedical fields.


Assuntos
Hidrogéis , Interações Hidrofóbicas e Hidrofílicas , Peptídeos , Hidrogéis/química , Peptídeos/química , Nanoestruturas/química , Tensoativos/química , Humanos , Animais
3.
Biomacromolecules ; 25(6): 3715-3723, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38723225

RESUMO

A majority of short peptide (≤7 amino acids) hydrogels are primarily assembled via cross ß-structure formation. In contrast to the natural trend, herein, we report the formation of supramolecular hydrogel from the ultrashort hybrid folded peptide composed of canonical α-amino acid and noncanonical γ-amino acid, Fmoc-γPhe-Phe-OH. The designed hybrid peptide hydrogel is composed of entangled fibers, has viscoelastic properties, exhibits proteolytic stability, and exhibits cytocompatibility with L929 fibroblast cells. Mutating the peptide sequence by altering the position of γPhe from the N-termini to C-termini transforms the self-assembly into crystalline aggregates. Combining FTIR, 2D NMR, and DFT calculations revealed that the hydrogel-forming peptide adopts a C9 H-bonded conformation, resembling the well-known γ-turn. However, the isomeric hybrid peptide adopts an extended structure. The present study highlights the importance of secondary structure in the higher order assembly of minimalist hybrid peptides and broadens the range of secondary structures to design short peptide-based hydrogels.


Assuntos
Hidrogéis , Peptídeos , Hidrogéis/química , Peptídeos/química , Camundongos , Estrutura Secundária de Proteína , Animais , Fibroblastos/efeitos dos fármacos
4.
Biomacromolecules ; 24(2): 807-824, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36649490

RESUMO

In recent years, immense attention has been devoted over the production of osteoinductive materials. To this direction, collagen has a dominant role in developing hard tissues and plays a crucial role in the biomineralization of these tissues. Here, we demonstrated for the first time the potential of the shortest molecular pentapeptide domain inspired from collagen toward mineralizing hydroxyapatite on peptide fibers to develop bone-filling material. Our simplistic approach adapted the easy and facile route of introducing the metal ions onto the peptide nanofibers, displaying adsorbed glutamate onto the surface. This negatively charged surface further induces the nucleation of the crystalline growth of hydroxyapatite. Interestingly, nucleation and growth of the hydroxyapatite crystals lead to the formation of a self-supporting hydrogel to construct a suitable interface for cellular interactions. Furthermore, microscopic and spectroscopic investigations revealed the crystalline growth of the hydroxyapatite onto peptide fibers. The physical properties were also influenced by this crystalline deposition, as evident from the hierarchical organization leading to hydrogels with enhanced mechanical stiffness and improved thermal stability of the scaffold. Furthermore, the mineralized peptide fibers were highly compatible with osteoblast cells and showed increased cellular biomarkers production, which further reinforced the potential application toward effectively fabricating the grafts for bone tissue engineering.


Assuntos
Substitutos Ósseos , Nanofibras , Engenharia Tecidual/métodos , Nanofibras/química , Colágeno/química , Fosfatos de Cálcio/química , Durapatita/química , Hidrogéis
5.
Biomacromolecules ; 24(11): 4923-4938, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37909341

RESUMO

Recently, peptide and sugar-based multicomponent systems have gained much interest in attaining the sophisticated structure and biofunctional complexity of the extracellular matrix (ECM). To this direction, we have designed for the first time a biologically relevant minimalist Cardin-motif peptide capable of binding ECM-derived glycosaminoglycans. Herein, we explored Cardin-motif peptide and heparin-based biomolecular matrix by employing simple noncovalent interactions at the molecular level. Interestingly, this peptide was inadequate to induce hydrogelation at ambient pH due to the presence of basic amino acids. However, addition of heparin successfully triggered its gelation at physiological pH following favorable electrostatic interactions with heparin. Importantly, the newly developed scaffolds displayed tunable nanofibrous morphology and superior mechanical properties as controlled simply by the differential mixing ratio of both biomolecular entities. Additionally, these composite scaffolds could closely mimic the complexity of ECM as they demonstrated superior biocompatibility and enhanced growth and proliferation of neural cells as compared to the peptide scaffold.


Assuntos
Heparina , Hidrogéis , Hidrogéis/química , Heparina/farmacologia , Heparina/química , Peptídeos/farmacologia , Peptídeos/química , Matriz Extracelular/química , Glicosaminoglicanos/metabolismo , Alicerces Teciduais/química
6.
Int J Inf Secur ; 22(2): 333-345, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36471814

RESUMO

Distributed Denial of Service (DDoS) attacks have emerged as the top security threat with the rise of e-commerce in recent years. Volumetric attacks are the most common DDoS attacks that aim to overwhelm the victim's bandwidth. The current mitigation methods use reactive filtering techniques that are not magical and straightforward solutions. In this paper, we propose a network architecture based on the capability to address the threat of DDoS attacks. Physically Unclonable Functions (PUFs) have emerged as a promising solution in security. Motivated by the capability approach, we put forward a network architecture where the routers use Transient Effect Ring Oscillator PUF to generate and verify capabilities. This novel hardware-based solution, to address the problem, has reduced the computational overhead of capability generation. Additionally, the destination has complete control over the incoming traffic in the proposed architecture, resulting in uninterrupted communication with the legitimate clients regardless of the attacker traffic. The large-scale simulation on an open-source Network Simulator (NS-3) has shown that the proposed architecture efficiently mitigates DDoS attacks to a large extend. With our proposed architecture, the throughput was hardly affected when attacker traffic was varied from 10 to 80%.

7.
Biomacromolecules ; 23(6): 2496-2511, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35522599

RESUMO

Multicomponent self-assembly is an emerging approach in peptide nanotechnology to develop nanomaterials with superior physical and biological properties. Inspired by the multicomponent nature of the native extracellular matrix (ECM) and the well-established advantages of co-assembly in the field of nanotechnology, we have attempted to explore the noncovalent interactions among the sugar and peptide-based biomolecular building blocks as an approach to design and develop advanced tissue scaffolds. We utilized TEMPO-oxidized nanofibrillar cellulose (TO-NFC) and a short ionic complementary peptide, Nap-FEFK, to fabricate highly tunable supramolecular hydrogels. The differential doping of the peptide into the TO-NFC hydrogel was observed to tune the surface hydrophobicity, microporosity, and mechanical stiffness of the scaffold. Interestingly, a differential cellular response was observed toward composite scaffolds with a variable ratio of TO-NFC versus Nap-FEFK. Composite scaffolds having a 10:1 (w/w) ratio of TO-NFC and the Nap-FEFK peptide showed enhanced cellular survival and proliferation under two-dimensional cell culture conditions. More interestingly, the cellular proliferation on the 10:1 matrix was found to be similar to that of Matrigel in three-dimensional culture conditions, which clearly indicated the potential of these hydrogels in advanced tissue engineering applications. Additionally, these composite hydrogels did not elicit any significant inflammatory response in Raw cells and supported their survival and proliferation, which further emphasized their ability to form versatile scaffolds for tissue regeneration. This multicomponent assembly approach to construct biomolecular composite hydrogels to access superior physical and biological properties within the scaffold is expected to improve the scope for designing novel ECM-mimicking biomaterials for regenerative medicine.


Assuntos
Celulose Oxidada , Hidrogéis , Óxidos N-Cíclicos , Hidrogéis/química , Peptídeos/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química
8.
Biomacromolecules ; 22(6): 2393-2407, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-33973785

RESUMO

Peptide self-assembly is gathering much attention due to the precise control it provides for the arrangement of functional moieties for the fabrication of advanced functional materials. It is desirable to use a physical, chemical, or biological trigger that can control the self-assembly process. In the current article, we have applied an enzyme to induce the peptide self-assembly of an aromatic peptide amphiphile, which modulates the supramolecular order in the final gel phase material. We accessed diverse peptide hydrogels from identical gelator concentrations by simply changing the enzyme concentration, which controlled the reaction kinetics and influenced the dynamics of self-assembly. Depending upon the concentration of the enzyme, a bell-shaped relationship was observed in terms of intermolecular interactions, morphology, and properties of the final gel phase material. The access of non-equilibrium structures was further demonstrated by fluorescence emission spectroscopy, circular dichroism spectroscopy, atomic force microscopy, transmission electron microscopy, and rheology. This strategy is applied to construct a charge-transfer hydrogel by doping the donor hydrogel with an acceptor moiety, which exhibits efficient energy transfer. Interestingly, such structural control at the nanoscopic level can further tune the energy-transfer efficiency by simply modulating the enzyme concentration.


Assuntos
Dipeptídeos , Hidrogéis , Transferência de Energia , Peptídeos , Pirenos
9.
Soft Matter ; 17(12): 3266-3290, 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33730140

RESUMO

The phenomenal advancement in regenerative medicines has led to the development of bioinspired materials to fabricate a biomimetic artificial extracellular matrix (ECM) to support cellular survival, proliferation, and differentiation. Researchers have diligently developed protein polymers consisting of functional sequences of amino acids evolved in nature. Nowadays, certain repetitive bioinspired polymers are treated as an alternative to synthetic polymers due to their unique properties like biodegradability, easy scale-up, biocompatibility, and non-covalent molecular associations which imparts tunable supramolecular architecture to these materials. In this direction, elastin has been identified as a potential scaffold that renders extensibility and elasticity to the tissues. Elastin-like polypeptides (ELPs) are artificial repetitive polymers that exhibit lower critical solution temperature (LCST) behavior in a particular environment than synthetic polymers and hence have gained extensive interest in the fabrication of stimuli-responsive biomaterials. This review discusses in detail the unique structural aspects of the elastin and its soluble precursor, tropoelastin. Furthermore, the versatility of elastin-like peptides is discussed through numerous examples that bolster the significance of elastin in the field of regenerative medicines such as wound care, cardiac tissue engineering, ocular disorders, bone tissue regeneration, etc. Finally, the review highlights the importance of exploring short elastin-mimetic peptides to recapitulate the structural and functional aspects of elastin for advanced healthcare applications.


Assuntos
Elastina , Hidrogéis , Materiais Biocompatíveis , Engenharia Biomédica , Matriz Extracelular , Proteínas da Matriz Extracelular , Engenharia Tecidual
10.
Langmuir ; 36(4): 1003-1013, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31865708

RESUMO

Collagen, the most abundant component of natural ECM, has attracted interest of scientific communities to replicate its multihierarchical self-assembling structure. Recent developments in collagen mimetic peptides were inclined toward the production of self-assembling short peptides capable of mimicking complex higher order structures with tunable mechanical properties. Here, we report for the first time, the crucial molecular design of oppositely charged collagen mimetic shortest bioactive pentapeptide sequences, as a minimalistic building block for development of next-generation biomaterials. Our rational design involves synthesis of two pentapeptides, where the fundamental molecular motif of collagen, that is, Gly-X-Y has been mutated at the central position with positively charged, lysine, and negatively charged, aspartate, residues. Depending on their overall surface charge, these peptides showed high propensity to form self-supporting hydrogel either at acidic or basic pH, which limits their biomedical applications. Interestingly, simple mixing of the two peptides was found to induce the coassembly of these designed peptides, which drives the formation of self-supporting hydrogel at physiological pH and thus enhanced the potential of exploring these peptides for biomedical purposes. This coassembly of ionic peptides was accompanied by the enhancement in the mechanical stiffness of the gels and reduction in overall zeta potential of the combined hydrogel, which provides the evidence for additional electrostatic interactions. Furthermore, the thixotropic nature of these gels offers an additional advantage of exploration of designer biomaterials as injectable gels. The nanofibers of coassembled hydrogel were found to be highly biocompatible to the fibroblast cells compared to the individual peptides, which was evident from their cytotoxicity studies. We anticipate that our rational design of ECM protein mimics in the form of short bioactive peptides will contribute significantly to the development of novel biomaterials and play a crucial role in the field of tissue engineering and regenerative medicines.


Assuntos
Colágeno/química , Peptídeos/química , Hidrogel de Polietilenoglicol-Dimetacrilato , Concentração de Íons de Hidrogênio , Íons/química , Substâncias Macromoleculares/química , Espectrometria de Massas , Estrutura Molecular , Peptídeos/síntese química , Eletricidade Estática
11.
Langmuir ; 36(41): 12107-12120, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32988205

RESUMO

Creating diverse nanostructures from a single gelator through modulating the self-assembly pathway has been gaining much attention in recent years. To this direction, we are exploring the effect of modulation of pH as a potential self-assembly pathway in governing the physicochemical properties of the final gel phase material. In this context, we used a classical nongelator with the ionic complementary sequence FEFK, which was rationally conjugated to an aromatic group naphthoxyacetic acid (Nap) at the N-terminal end to tune its gelation behavior. Interestingly, the presence of oppositely charged amino acids in the peptide amphiphile resulted in pH-responsive behavior, leading to the formation of hydrogels over a wide pH range (2.0-12.0); however, their structures differ significantly at the nanoscale. Thus, by simply manipulating the overall charge over the exposed surface of the peptide amphiphiles as a function of pH, we were able to access diverse self-assembled nanostructures within a single gelator domain. The charged state of the gelator at the extreme pH (2.0, 12.0) led to a thinner fiber formation, in contrast to the thicker fibers observed near the physiological pH owing to charge neutralization, thus promoting the lateral association. Such variation in molecular packing was found to be further reflected in the variable mechanical strengths of the peptide hydrogels obtained at different pH values. Moreover, the gelation of the peptide at physiological pH offers an additional advantage to explore this hydrogel as a cell culture scaffold. We anticipate that our study on controlling the self-assembly pathway of the ionic complementary peptide amphiphile can be an elegant approach to access diverse self-assembled materials, which can expand the zone of its applicability as a stimuli-responsive biomaterial.

12.
Biomacromolecules ; 21(10): 4180-4193, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-32786522

RESUMO

In recent years, the molecular self-assembly approach has witnessed a sudden surge in coassembly strategy to achieve extensive control over accessing diverse nanostructures and functions. To this direction, peptide-peptide coassembly has been explored to some extent in the literature, but protein-peptide coassembly is still in its infancy for controlling the self-assembling properties. To the best of our knowledge, our study illustrated the merits of protein-peptide coassembly toward inducing gelation to a nongelator dipeptide sequence, for the first time. This simplistic approach could provide access to diverse mechanical and structural properties within a single gelator domain at identical concentrations with a simple variation in the protein concentrations. Interestingly, the protein-peptide interactions could transform aggregate-like structures into fibrillar nanostructures. The study attempts to provide the proof of concept for the nonspecific protein-peptide interactions purely based on simple noncovalent interactions. The range of dissociation constants and binding energies obtained from bioloyer interferometry and docking studies confirmed the involvement of noncovalent interactions in protein-peptide coassembly, which triggers gelation. Moreover, different binding affinities of a protein toward an individual peptide essentially demonstrated a route to achieve precise control over differential self-assembling properties. Another important aspect of this study was entrapment of an enzyme protein within the gel network during coassembly without inhibiting enzyme activity, which can serve as a scaffold for catalytic reactions. The present study highlights the nonconventional way of protein-peptide interactions in triggering self-assembly in a nonassembling precursor. We anticipate that fundamental insights into the intermolecular interactions would lead to novel binary supramolecular hydrogels that can be developed as a next generation biomaterial for various biomedical applications.


Assuntos
Nanoestruturas , Peptídeos , Dipeptídeos , Hidrogéis
13.
Chemistry ; 25(33): 7881-7887, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-30945773

RESUMO

The possibility of using differential pre-heating prior to supramolecular gelation to control the balance between hydrogen-bonding and aromatic stacking interactions in supramolecular gels and obtain consequent systematic regulation of structure and properties is demonstrated. Using a model aromatic peptide amphiphile, Fmoc-tyrosyl-leucine (Fmoc-YL) and a combination of fluorescence, infrared, circular dichroism and NMR spectroscopy, it is shown that the balance of these interactions can be adjusted by temporary exposure to elevated temperatures in the range 313-365 K, followed by supramolecular locking in the gel state by cooling to room temperature. Distinct regimes can be identified regarding the balance between H-bonding and aromatic stacking interactions, with a transition point at 333 K. Consequently, gels can be obtained with customizable properties, including supramolecular chirality and gel stiffness. The differential supramolecular structures also result in changes in proteolytic stability, highlighting the possibility of obtaining a range of supramolecular architectures from a single molecular structure by simply controlling the pre-assembly temperature.

14.
Langmuir ; 35(17): 5878-5889, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30916565

RESUMO

The fundamental understanding of the detailed relationship between molecular structure and material function remains a challenging task, until now. In order to understand the relative contribution of aromatic moieties and hydrophobicity of amino acid chains, we designed a library of ultrashort amyloid-like peptides based on Ar-Phe-X (where "Ar" represents different aromatic moieties and "X" represents amino acids having varied side-chain functionalities). Our research clearly indicated that the alteration in the size and hydrophobicity of the aromatic capping play a crucial role compared to the subtle change in the amino acid sequence of the dipeptide in dictating the final self-assembled structure and properties of these short peptide amphiphiles. Further, we explored our detailed understanding toward the controlled synthesis of bioinspired organic-inorganic hybrids. For the first time, we established the differential role of aliphatic and aromatic hydroxyl moieties toward the in situ shape-controlled synthesis of gold nanoparticles in three-dimensional nanostructures of hydrogels. To the best of our knowledge, it is the first report which demonstrated the formation of rectangular platonic gold nanoparticles using simple dipeptide hydrogels, exhibiting pH-dependent size control. Our study shows promising implications in bottom-up nanofabrication of next-generation nanomaterials with emergent properties.


Assuntos
Proteínas Amiloidogênicas/química , Dipeptídeos/química , Hidrogéis/química , Nanopartículas Metálicas/química , Proteínas Amiloidogênicas/síntese química , Dipeptídeos/síntese química , Ouro/química , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Multimerização Proteica , Reologia
15.
Biomacromolecules ; 20(7): 2610-2624, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31185164

RESUMO

Controlling the self-assembly pathways can be an effective means to create complex multifunctional structures based on a single gelator design. To this direction, an ion mediated approach to control and direct supramolecular structure of the low molecular weight peptide hydrogelator would be an excellent methodology for bottom-up nanofabrication of these advanced functional materials. Our work primarily aims to understand the role of different metal ions as well as anions in modulating the self-assembly of the peptide amphiphiles. Our approach relies on rational incorporation of histidine in the peptide amphiphile, which can impart an ion responsive behavior to the hydrogels. Interestingly, the self-assembly pathway of histidine based dipeptide amphiphile was found to be largely influenced by various metal salts. A gel to sol transition occurred at physiological pH in the presence of Cu2+, Ni2+ and Co2+ ions, owing to their strong interactions with the histidine, thus shifting the gelation to pH 3.0. However, in the case of Fe2+ and Mn2+, the weak interactions of histidine-metal ion can still hold the gel at physiological pH but gel strength was significantly decreased. Our studies provide a clear insight into this ion-responsive behavior across a wide pH range, which is mainly governed by the stability of a peptide-metal ion complex as per Irving-Williams series. Moreover, anions also influenced the mechanical strength as well as morphology of the nanostructures owing to their differential interaction with water as depicted in the Hofmeister series of anions. This bioinspired approach will provide an elegant strategy for accessing diverse structures, which are "out of equilibrium" and otherwise only accessible through differential molecular design. We envisage that our systematic studies on histidine-metal ion interaction can be an extremely useful methodology, which will pave a way to design and develop the stimuli responsive biomaterials.


Assuntos
Dipeptídeos , Histidina/química , Metais Pesados/química , Sais/química , Dipeptídeos/síntese química , Dipeptídeos/química , Concentração de Íons de Hidrogênio
16.
Small ; 10(5): 973-9, 2014 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-24027125

RESUMO

For the development of applications and novel uses for peptide nanostructures, robust routes for their surface functionalization, that ideally do not interfere with their self-assembly properties, are required. Many existing methods rely on covalent functionalization, where building blocks are appended with functional groups, either pre- or post-assembly. A facile supramolecular approach is demonstrated for the formation of functionalized nanofibers by combining the advantages of biocatalytic self-assembly and surfactant/gelator co-assembly. This is achieved by enzymatically triggered reconfiguration of free flowing micellar aggregates of pre-gelators and functional surfactants to form nanofibers that incorporate and display the surfactants' functionality at the surface. Furthermore, by varying enzyme concentration, the gel stiffness and supramolecular organization of building blocks can be varied.


Assuntos
Biocatálise , Nanofibras/química , Fosfatase Alcalina/metabolismo , Cromatografia Líquida de Alta Pressão , Nanofibras/ultraestrutura , Oligopeptídeos/química , Espectrometria de Fluorescência , Eletricidade Estática , Tensoativos/química
17.
J Am Chem Soc ; 135(45): 16789-92, 2013 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-24147566

RESUMO

We demonstrate the formation of supramolecular peptide nanofibers that display dynamic instability; i.e., they are formed by competing assembly and disassembly reactions, where assembly is favored away from equilibrium. The systems are based on competitive catalytic transacylation and hydrolysis, producing a self-assembling aromatic peptide amphiphile from amino acid precursors that temporarily exceeds the critical gelation concentration, until the competing hydrolytic reaction takes over. Analysis by atomic force microscopy shows consecutive nanofiber formation and shortening. The process results in macroscopically observable temporary hydrogelation, which may be repeated upon refueling the system with further addition of the chemically activated amino acid precursor. Nonequilibrium nanostructures open up opportunities for mimicry of the behavior of dynamic gels found in natural systems and provide components for future adaptive nanotechnologies.


Assuntos
Géis/química , Nanofibras/química , Nanofibras/ultraestrutura , Peptídeos/química , Acilação , Aminoácidos/química , Biocatálise , Hidrólise , Nanotecnologia/métodos
18.
Langmuir ; 29(46): 14321-7, 2013 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-24144273

RESUMO

We demonstrate the preparation of peptide gel microparticles that are emulsified and stabilized by SiO2 nanoparticles. The gels are composed of aromatic peptide amphiphiles 9-fluorenylmethoxycarbonyldiphenylalanine (Fmoc-FF) coassembled with Fmoc-amino acids with different functional groups (S: serine; D: aspartic acid; K: lysine; and Y: tyrosine). The gel phase provides a highly hydrated matrix, and peptide self-assembly endows the matrix with tunable chemical environments which may be exploited to support and stabilize proteins. The use of Pickering emulsion to stabilize these gel particles is advantageous through avoidance of surfactants that may denature proteins. The performance of enzyme lipase B immobilized in pickering/gel microparticles with different chemical functionalities is investigated by studying transesterification in heptane. We show that the use of Pickering particles enhances the performance of the enzyme, which is further improved in gel-phase systems, with hydrophilic environment provided by Fmoc-FF/S giving rise to the best catalytic performance. The combination of a tunable chemical environment in gel phase and Pickering stabilization described here is expected to prove useful for areas where proteins are to be exploited in technological contexts such as biocatalysis and also in other areas where protein performance and activity are important, such as biosensors and bioinspired solar fuel devices.


Assuntos
Biocatálise , Peptídeos/química , Caprilatos/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Esterificação , Fluorenos/química , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Géis , Heptanos/química , Lipase/química , Lipase/metabolismo , Modelos Moleculares , Nanopartículas/química , Octanóis/química , Conformação Proteica , Dióxido de Silício/química
19.
Biomacromolecules ; 14(12): 4368-76, 2013 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-24256076

RESUMO

Molecular self-assembly provides a versatile route for the production of nanoscale materials for medical and technological applications. Herein, we demonstrate that the cooperative self-assembly of amphiphilic small molecules and proteins can have drastic effects on supramolecular nanostructuring of resulting materials. We report that mesoscale, fractal-like clusters of proteins form at concentrations that are orders of magnitude lower compared to those usually associated with molecular crowding at room temperature. These protein clusters have pronounced effects on the molecular self-assembly of aromatic peptide amphiphiles (fluorenylmethoxycarbonyl- dipeptides), resulting in a reversal of chiral organization and enhanced order through templating and binding. Moreover, the morphological and mechanical properties of the resultant nanostructured gels can be controlled by the cooperative self-assembly of peptides and protein fractal clusters, having implications for biomedical applications where proteins and peptides are both present. In addition, fundamental insights into cooperative interplay of molecular interactions and confinement by clusters of chiral macromolecules is relevant to gaining understanding of the molecular mechanisms of relevance to the origin of life and development of synthetic mimics of living systems.


Assuntos
Dipeptídeos/química , Hidrogéis/química , Lactoglobulinas/química , Soroalbumina Bovina/química , Aminoácidos/química , Animais , Bovinos , Dicroísmo Circular , Módulo de Elasticidade , Fluorenos/química , Microscopia de Força Atômica , Multimerização Proteica , Estrutura Secundária de Proteína , Estereoisomerismo
20.
Nanoscale ; 15(16): 7537-7558, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37022122

RESUMO

Short bioactive peptide-based supramolecular hydrogels are emerging as interesting candidates for developing scaffolds for tissue engineering applications. However, proteins and peptides represent only a single class of molecules present in the native ECM, thus, recapitulating the complete ECM microenvironment via only peptide-based biomaterials is extremely challenging. In this direction, complex multicomponent-based biomaterials have started gaining importance for achieving the biofunctional complexity and structural hierarchy of the native ECM. Sugar-peptide complexes can be explored in this direction as they provide essential biological signaling required for cellular growth and survival in vivo. In this direction, we explored the fabrication of an advanced scaffold by employing heparin and short bioactive peptide interactions at the molecular level. Interestingly, the addition of heparin into the peptide has significantly modulated the supramolecular organization, nanofibrous morphology and the mechanical properties of the scaffold. Additionally, the combined hydrogels demonstrated superior biocompatibility as compared to the peptide counterpart at certain ratios. These newly developed scaffolds were also observed to be stable under 3-D cell culture conditions and supported cellular adhesion and proliferation. Most importantly, the inflammatory response was also minimized in the case of combined hydrogels as compared to heparin. We expect that this approach of using simple non-covalent interactions between the ECM-inspired small molecules to fabricate biomaterials with improved mechanical and biological properties could advance the current knowledge on designing ECM mimetic biomaterials. Such an attempt would create a novel, adaptable and simplistic bottom-up strategy for the invention of new and more complex biomaterials of ECM origin with advanced functions.


Assuntos
Matriz Extracelular , Heparina , Heparina/farmacologia , Heparina/química , Matriz Extracelular/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/metabolismo , Engenharia Tecidual , Peptídeos/farmacologia , Peptídeos/química , Hidrogéis/farmacologia , Hidrogéis/química , Alicerces Teciduais
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