Understanding the Molecular Mechanisms of Polyphenol Inhibition of Amyloid ß Aggregation.

Alzheimer's disease (AD) is highly associated with self-aggregation of amyloid ß (Aß) proteins into fibrils. Inhibition of Aß aggregation by polyphenols is one of the major therapeutic strategies for AD. Among them, four polyphenols (brazilin, resveratrol, hematoxylin, and rosmarinic acid) have been reported to be effective at inhibiting Aß aggregation, but the inhibition mechanisms are still unclear. In this work, these four polyphenols were selected to explore their interactions with the Aß17-42 pentamer by molecular dynamics simulation. All four polyphenols can bind to the pentamer tightly but prefer different binding sites. Conversion of the ß-sheet to the random coil, fewer interchain hydrogen bonds, and weaker salt bridges were observed after binding. Interestingly, different Aß17-42 pentamer destabilizing mechanisms for resveratrol and hematoxylin were found. Resveratrol inserts into the hydrophobic core of the pentamer by forming hydrogen bonds with Asp23 and Lys28, while hematoxylin prefers to bind beside chain A of the pentamer, which leads to ß-sheet offset and dissociation of the ß1 sheet of chain E. This work reveals the interactions between the Aß17-42 pentamer and four polyphenols and discusses the relationship between inhibitor structures and their inhibition mechanisms, which also provides useful guidance for screening effective Aß aggregation inhibitors and drug design against AD.

Delivery of Bioactive Albumin from Multi-Functional Polyampholyte Hydrogels.

Tissue engineered scaffolds are currently being explored to aid in healing and regeneration of non-union fractures in bone. Additionally, albumin has been demonstrated to provide benefits to healing when applied to injury sites. This paper focuses on delivery of calcium modified, bioactive bovine serum albumin (BSA) from a multi-functional polyampholyte polymer scaffold. First, the inherent nonfouling and conjugation properties of the polyampholyte hydrogel were verified to determine the impact of calcium exposure. The polyampholyte hydrogel delivery platform was then assessed with calcium titrations and osteoblast-like cell (MC3T3-E1) adhesion, proliferation, and viability evaluations. Finally, integrin inhibitors were used to identify the binding mechanisms that mediate cell adhesion to the calcium-modified BSA-conjugated hydrogels. An increase in cell adhesion was observed following calcium exposure up to 0.075 M, although this and higher calcium concentrations affected hydrogel stability and cell growth. BSA exposed to 0.05 M calcium and delivered from polyampholyte hydrogels promoted the most promising viable cell adhesion over 7 days. Cell adhesion to the calcium-modified BSA-conjugated hydrogels appeared to be regulated by arginine-glycine-aspartic acid (RGD) and collagen specific integrins. These results demonstrate that the delivery of calcium modified BSA from an implantable polymer scaffold is promising for bone tissue engineering applications.

Spontaneously Restoring Specific Bioaffinity of RGD in Linear RGD-containing Peptides by Conjugation with Zwitterionic Dendrimers.

Peptides are more versatile than small molecule drugs, but their specific bioaffinities are usually lower than their original native proteins because of the loss of preferred conformations. To overcome this key obstacle, we demonstrated a hydrogen bond-induced conformational constraint method to enhance the specific bioaffinities of peptides to achieve a high success rate by using linear RGD-containing peptides as a model of bioactive peptides. By performing molecular simulation, we found that the chemically immobilized linear CRGDS via cysteine (C) at the N-terminus on zwitterionic PAMAM G-5 can not only spontaneously restore the natural conformation of the RGD segment through the assistance of the dynamic hydrogen bond from serine (S) at the C-terminus of the peptide, but it can also narrow the distribution of all possible conformations. Consequently, the conjugates showed comparable or even better high affinity than native proteins without the use of conventional, labor-intensive, synthesis-based structure search methods to construct a binding conformation. In addition, the conjugates showed globular protein-like characteristics chemically, physically, and physiologically. They exhibited not only high efficacy and biosafety both in vitro and in vivo, but they also showed extremely high thermostability even upon boiling in a solution. This approach offers great design flexibility for reviving functional peptides without impairing their high specific affinity for their targets. STATEMENT OF SIGNIFICANCE: In this work, we developed a swift approach to spontaneously restore the natural conformation of a linear peptide from a nature protein and thus enhance its specific bioaffinity instead of constructing a binding conformation by the labor-intensive, synthesis-based structure search method. In details, our new approach involves dynamically constraining the linear peptide on a zwitterionic PAMAM G-5 surface by a combination of chemical bonding at one terminus and dynamic hydrogen bonding at the other terminus of the linear peptide. The zwitterionic background offers abundant interaction sites for hydrogen bonding as well as resistance to nonspecific interactions. This approach fully restores the specific bioaffinity of RGD segments on a zwitterionic PAMAM G-5 through only one conjugation point at the C-terminus of the peptide. Moreover, the bioaffinity of all three types of RGD-containing peptides is successfully restored, which indicates the high rate of success of this approach in affinity restoring.

Paired Simulations and Experimental Investigations into the Calcium-Dependent Conformation of Albumin.

Serum albumin is the most abundant protein in blood plasma, and it is involved in multiple biological processes. Serum albumin has recently been adapted for improving biomaterial integration with bone tissue, and studies have shown the importance of this protein in bone repair and regeneration. However, the mechanism of action is not yet clear. In stark contrast, other studies have demonstrated that albumin blocks cell adhesion to surfaces, which is seen as a limitation to its bone healing role. These apparent contradictions suggest that the conformation of albumin facilitates its bioactivity, leading to enhanced bone repair. Serum albumin is known to play a major role in maintaining the calcium ion concentration in blood plasma. Due to the prevalence of calcium at bone repair and regeneration sites, it has been hypothesized that calcium binding to serum albumin triggers a conformational change, leading to bioactivity. In the current study, molecular modeling approaches including molecular docking, atomic molecular dynamics (MD) simulation, and coarse-grained MD simulation were used to test this hypothesis by investigating the conformational changes induced in bovine serum albumin by interaction with calcium ions. The computational results were qualitatively validated with experimental Fourier-transform infrared spectroscopy analysis. We find that free calcium ions in solution transiently bind with the three major loops in albumin, triggering a conformational change where N-terminal and C-terminal domains separate from each other in a partial unfolding process. The separation distance between these domains was found to correlate with the calcium ion concentration. The experimental data support the simulation results showing that albumin has enhanced conformational heterogeneity upon exposure to intermediate levels of calcium, without any significant secondary structure changes.

A Robust Approach to In Situ Exsolve Highly Dispersed and Stable Electrocatalysts.

Catalysts made of in situ exsolved metal nanoparticles often demonstrate promising activity and high stability in many applications. However, the traditional approach is limited by perovskites as prevailing precursor and requires high temperature typically above 900 K. Here, with the guidance of theoretical calculation, an unprecedented and substantially facile technique is demonstrated for Cu nanoparticles exsolved from interstitially Cu cations doped nickel-based hydroxide, which is accomplished swiftly at room temperature and results in metal nanoparticles with a quasi-uniform size of 4 nm, delivering an exceptional CO faradaic efficiency of 95.6% for the electrochemical reduction of CO2 with a notable durability. This design principle is further proven to be generally applicable to other metals and foregrounded for guiding the development of advanced catalytic materials.

Enhancement and mechanisms of MC3T3-E1 osteoblast-like cell adhesion to albumin through calcium exposure.

Serum albumin is the most prominent protein in blood, and it aids in bone fracture healing, though the manner through which enhanced healing occurs is not well understood. This study investigates the influence of calcium on the bioactivity of albumin due to the prevalence of calcium at bone injury sites. Bovine serum albumin (BSA) was exposed to varying concentrations of calcium, adsorbed to tissue culture polystyrene, and the subsequent BSA-coated surfaces were evaluated with calcium titration, and cell adhesion, viability, and binding inhibition studies. Calcium-modified BSA improved overall MC3T3-E1 osteoblast-like cell adhesion, although high calcium concentrations induced cell death. Inhibiting specific integrins revealed that without calcium exposure, cell binding to BSA was primarily mediated by integrins that typically bind to the GFOGER sequence of collagen. As calcium exposure increases, the primary binding interaction transitioned to integrins known to bind RGD. However, cell binding to calcium-modified BSA was not completely eliminated during the inhibition studies indicating additional unidentified binding interactions occur. Overall, these results suggest that the exposure to calcium induces conformational changes that affect the cell-binding bioactivity of BSA, which may explain the beneficial impact of albumin in bone tissue.

Assessment of the performance of nonfouling polymer hydrogels utilizing citizen scientists.

To facilitate longer duration space travel, flight crew sickness and disease transmission amongst the crew must be eliminated. High contact surfaces within space vehicles provide an opportunity for bacterial adhesion, which can lead to biofilm formation or disease transmission. This study evaluates the performance of several nonfouling polymers using citizen science, to identify the best performing chemistry for future applications as bacteria resistant coatings. The specific polymer chemistries tested were zwitterionic sulfobetaine methacrylate (SBMA), and polyampholytes composed of [2-(acryloyloxy)ethyl] trimethylammonium chloride and 2-carboxyethyl acrylate (TMA/CAA), or TMA and 3-sulfopropyl methacrylate (TMA/SA). Each polymer chemistry is known to exhibit bacteria resistance, and this study provides a direct side-by-side comparison between the chemistries using a citizen science approach. Nearly 100 citizen scientists returned results comparing the performance of these polymers over repeat exposure to bacteria and 30 total days of growth. The results demonstrate that TMA/CAA polyampholyte hydrogels show the best long-term resistance to bacteria adhesion.

Synthesis of a zwitterionic N-Ser-Ser-C dimethacrylate cross-linker and evaluation in polyampholyte hydrogels.

Polyampholyte hydrogels are attractive materials for tissue engineering scaffolds as they offer a wide variety of features including nonfouling, selective protein delivery, and tunable physical characteristics. However, to improve the potential performance of these materials for in vivo applications, there is a need for a higher diversity of zwitterionic cross-linker species to replace commonly used ethylene glycol (EG) based chemistries. Towards this end, the synthesis of a dipeptide based zwitterionic cross-linker, N-Ser-Ser-C dimethacrylate (S-S) from N-Boc-l-serine is presented. The strategy utilized a convergent coupling of methacrylated serine partners followed by careful global deprotection to yield the zwitterionic cross-linker with good overall yields. This novel cross-linker was incorporated into a polyampholyte hydrogel and its physical properties and biocompatibility were compared against a polyampholyte hydrogel synthesized with an EG-based cross-linker. The S-S cross-linked hydrogel demonstrated excellent nonfouling performance, while promoting enhanced cellular adhesion to fibrinogen delivered from the hydrogel. Therefore, the results suggest that the S-S cross-linker will demonstrate superior future performance for in vivo applications.

Peritoneal adhesions: Occurrence, prevention and experimental models.

Peritoneal adhesions (PA) are a postoperative syndrome with high incidence rate, which can cause chronic abdominal pain, intestinal obstruction, and female infertility. Previous studies have identified that PA are caused by a disordered feedback of blood coagulation, inflammation, and fibrinolysis. Monocytes, macrophages, fibroblasts, and mesothelial cells are involved in this process, and secreted signaling molecules, such as tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), tissue plasminogen activator (tPA), and type 1 plasminogen activator inhibitor (PAI-1), play a key role in PA development. There have been many attempts to prevent PA formation by anti-PA drugs, barriers, and other therapeutic methods, but their effectiveness has not been widely accepted. Treatment by biomaterial-based barriers is believed to be the most promising method to prevent PA formation in recent years. In this review, the pathogenesis, treatment approaches, and animal models of PA are summarized and discussed to understand the challenges faced in the biomaterial-based anti-PA treatments.

Enhanced Biocompatibility of Polyampholyte Hydrogels.

Tissue-engineered scaffolds encounter many challenges including poor integration with native tissue. Nonspecific protein adsorption can trigger the foreign body response leading to encapsulation and isolation from the native injured tissue. This concern is mitigated with nonfouling polymer scaffolds. This study investigates the long-term biocompatibility of a nonfouling polyampholyte system composed of positively charged [2-(acryloyloxy)ethyl]trimethylammonium chloride monomers and negatively charged 2-carboxyethyl acrylate monomers, cross-linked with triethylene glycol dimethacrylate. This system has previously shown resistance to nonspecific protein adsorption and short-term cell attachment via conjugated proteins. However, longer-term cell survival has not been evaluated with this system. First, the environmental pH was monitored with varying amounts of counter ions present in the hydrogel synthesis buffer. The lowest level (3 M NaOH) and the level that resulted in pH values closest to physiological conditions (6.7 M NaOH) were chosen for further investigation. These two formulations were then compared in terms of their contact angle, qualitative protein adsorption and conjugation capacity, and quantitative cell adhesion, proliferation, and viability. The 3 M NaOH formulation showed higher initial protein conjugation and cell adhesion compared to the 6.7 M NaOH formulation. However, the 3 M NaOH hydrogels had low cell viability after 24 h due to the acidic component release into the culture environment. The 6.7 M NaOH formulation showed a lower initial conjugation and cell adhesion but overcame this limitation by providing a stable environment that maintained cell viability for over 5 days. The 6.7 M NaOH polyampholyte hydrogel formulation shows increased biocompatibility, while maintaining resistance to nonspecific protein adsorption, as demonstrated by the targeted cell adhesion and proliferation. Therefore, this polyampholyte formulation demonstrates strong potential as a tissue-engineered scaffold.

Evaluation of chlorine substituted hydroxyapatite (ClHAP)/polydopamine composite coatings on Ti64.

Titanium (Ti) and its alloys (especially Ti-6Al-4V or Ti64) are commonly used as load-bearing implants because of their biocompatibility and resistance to fatigue and corrosion. However, Ti/alloys are bio-inert metals and not prone to osseointegration. In order to further improve the bioactivity and osseointegration of Ti64, this study evaluated the modification of the Ti64 surface with a deposited chlorine substituted hydroxyapatite (ClHAP)/polydopamine (Pda) composite coating. Pda serves as an adhesion molecule and ClHAP releases slight acidity that stimulates osteoclastic activity. The composite coating with 10-30 % ClHAP particles is shown to promote bioactivity as evidenced by osteoblast proliferation. Therefore, this coating approach may enhance osseointegration in vivo.

Degradation of gas-phase o-xylene via combined non-thermal plasma and Fe doped LaMnO3 catalysts: Byproduct control.

A series of Fe doped LaMnO3 catalysts were prepared to control the production of byproducts such as O3, N2O, and CO, during the degradation of volatile organic compounds with a non-thermal plasma. Eliminating these potentially toxic byproducts will make non-thermal plasma technologies applicable for a wider range of commercial applications. The modified LaMnO3 catalysts are combined in NTP-catalysis reactor with optimal configuration. Experimental results show that doping Fe on LaMnO3 catalysts can not only enhance the oxidation of o-xylene, but also lower the emission levels of byproducts. LaMn0.9Fe0.1O3 catalyst shows the best catalytic activity among the formulations tested herein. In addition to the strong mineralization of 88.1 %, the catalyst has the highest performance for o-xylene conversion (91.3 %), O3 inhibition efficiency (84.9 %), and N2O inhibition efficiency (61.2 %) due to the strong concentration of active oxygen species on the surface of the catalyst. Moreover, the high reducibility of Fe3+ demonstrated with H2-TPR (hydrogen temperature-programed reduction) further enhances the removal of O3 by oxygen species exchange between Mn3+/Mn4+ and Fe2+/Fe3+.

Impacts of cross-linker chain length on the physical properties of polyampholyte hydrogels.

Polymeric tissue engineering scaffolds have shown promise to aid in regeneration and repair of damaged tissue. In particular, nonfouling polymers have been proposed for eliminating biomaterial-induced concerns such as infection, scarring, and rejection by the immune system. Polyampholyte polymers are one class of nonfouling polymers that are composed of an equimolar mixture of positively and negatively charged monomer subunits. They possess nonfouling properties, bioactive molecule conjugation capabilities, and tunable mechanical properties. In this study, the influence of the cross-linker species on the degradation behavior, mechanical strength, and nonfouling properties of polyampholytes composed of a 1:1 molar ratio of [2-(acryloyloxy)ethyl] trimethylammonium chloride (positively charged) and 2-carboxyethyl acrylate (negatively charged) monomers was investigated. Specifically, the impact of ethylene glycol repeat units on the overall material performance was evaluated by synthesizing and characterizing hydrogels containing di-, tri-, and tetra-ethylene glycol dimethacrylate cross-linker species. The degradation studies were conducted for over 100 days in Sorenson's buffer with pH values of 4.5, 7.4, and 9.0 by tracking the swelling behavior and weight change over time. The mechanical properties were assessed using compression and tensile testing to failure. The retention of the nonfouling and protein conjugation capabilities was demonstrated using fluorescently labeled bovine serum albumin. The results demonstrate the tunability of both degradation behavior and mechanical properties through the cross-linker selection, without impacting the underlying nonfouling and biomolecule delivery capabilities. Therefore, it is concluded that polyampholyte hydrogels represent a promising platform for tissue engineering.

Key features and updates for origin 2018.

OriginLab's newest version update to Origin and OriginPro includes ease-of-use features, like Origin Central updates and creation of an App Center, as well as larger changes like the addition of Unicode characters, alteration to how user files are stored and visually searched, and user input formula in cells within worksheets. These features add additional value to an already powerful data analysis and plotting software package.

Probing the influence of SIBLING proteins on collagen-I fibrillogenesis and denaturation.

Bone tissue is comprised of collagen, non-collagenous proteins, and hydroxyapatite and the SIBLING (small integrin binding, N-linked glycoprotein) family of proteins is the primary group of non-collagenous proteins. By replicating the native interactions between collagen and the SIBLING proteins at the interface of an implant, it is believed that a bone scaffold will more easily integrate with the surrounding tissue. In this work, bone sialoprotein, osteopontin (OPN), dentin sialoprotein (DSP), dentin phosphoprotein (DPP), C-terminal fragment of dentin matrix protein 1 (DMP1-C), and proteoglycan versions of DSP (DSP-PG) and DMP1 (DMP1-PG) were tested individually to determine their roles in collagen fibrillogenesis and the prevention of denaturation. It was shown that DSP and DPP slowed down fibrillogenesis, while other SIBLINGs had limited impact. In addition, the denaturation time was faster in the presence of DSP and OPN, indicating a negative impact. The role of calcium ions in these processes was also investigated. The presence of calcium ions sped up fibrillogenesis in all scenarios tested, but it had a negative impact by reducing the extent. Calcium also sped up the denaturation in most cases, with the exception of DMP1-C and DSP where the opposite was seen. Calcium had a similar effect on the proteoglycan variants in the fibrillogenesis process, but had no impact on the denaturation process in the presence of these two. It is believed that incorporating DMP1-C or DSP on the surface of a bone implant may improve the collagen interactions with the implant, thereby facilitating improved osteointegration.

Polyampholyte Hydrogels in Biomedical Applications.

Polyampholytes are a class of polymers made up of positively and negatively charged monomer subunits. Polyampholytes offer a unique tunable set of properties driven by the interactions between the charged monomer subunits. Some tunable properties of polyampholytes include mechanical properties, nonfouling characteristics, swelling due to changes in pH or salt concentration, and drug delivery capability. These characteristics lend themselves to multiple biomedical applications, and this review paper will summarize applications of polyampholyte polymers demonstrated over the last five years in tissue engineering, cryopreservation and drug delivery.

Characterizing Drug Release from Nonfouling Polyampholyte Hydrogels.

Controlled delivery of bioactive signaling molecules and drugs is essential for the development of the next generation of tissue regeneration scaffolds. However, these molecules must be delivered from a nonfouling platform, so that the therapeutic role is not masked by the naturally occurring foreign body response. Therefore, the purpose of this study is to characterize the release profiles of three pseudodrug molecules from a nonfouling polyampholyte hydrogel to gain insight into the potential for this platform to serve as a tissue regeneration scaffold. Hydrogels composed of equimolar concentrations of [2-(acryloyloxy)ethyl] trimethylammonium chloride (TMA) and 2-carboxyethyl acrylate (CAA) monomers were synthesized in the presence of caffeine, methylene blue, or metanil yellow. Then the release of these three molecules was tracked as a function of the hydrogel cross-linker density, the solution pH, and the solution ionic strength. The results suggest that the release of the neutral caffeine molecule is dictated by diffusion alone, while the release of the two charged pseudodrug molecules are controlled by their interactions with the charged regions of the TMA and CAA monomer subunits. These interactions are clearly impacted by solution pH and ionic strength leading to clear changes in the rate of release and extent of release for metanil yellow and methylene blue. Additionally, an enzyme-linked immunosorbent assay was used to confirm that the TMA:CAA hydrogels retain their nonfouling characteristics following the release of the pseudodrug molecules. When these results are combined with the literature related to TMA:CAA hydrogels, it is concluded that this system represents a promising multifunctional platform for both short-term and long-term delivery of bioactive molecules for tissue regeneration.

PEG Functionalization of Whispering Gallery Mode Optical Microresonator Biosensors to Minimize Non-Specific Adsorption during Targeted, Label-Free Sensing.

Whispering Gallery Mode (WGM) optical microresonator biosensors are a powerful tool for targeted detection of analytes at extremely low concentrations. However, in complex environments, non-specific adsorption can significantly reduce their signal to noise ratio, limiting their accuracy. To overcome this, poly(ethylene glycol) (PEG) can be employed in conjunction with appropriate recognition elements to create a nonfouling surface capable of detecting targeted analytes. This paper investigates a general route for the addition of nonfouling elements to WGM optical biosensors to reduce non-specific adsorption, while also retaining high sensitivity. We use the avidin-biotin analyte-recognition element system, in conjunction with PEG nonfouling elements, as a proof-of-concept, and explore the extent of non-specific adsorption of lysozyme and fibrinogen at multiple concentrations, as well as the ability to detect avidin in a concentration-dependent fashion. Ellipsometry, contact angle measurement, fluorescence microscopy, and optical resonator characterization methods were used to study non-specific adsorption, the quality of the functionalized surface, and the biosensor's performance. Using a recognition element ratio to nonfouling element ratio of 1:1, we showed that non-specific adsorption could be significantly reduced over the controls, and that high sensitivity could be maintained. Due to the frequent use of biotin-avidin-biotin sandwich complexes in functionalizing sensor surfaces with biotin-labeled recognition elements, this chemistry could provide a common basis for creating a non-fouling surface capable of targeted detection. This should improve the ability of WGM optical biosensors to operate in complex environments, extending their application towards real-world detection.

Development of zwitterionic polymer-based doxorubicin conjugates: tuning the surface charge to prolong the circulation and reduce toxicity.

Polymer-drug conjugates are commonly used as nano drug vehicles (NDVs) to delivery anticancer drugs. Zwitterionic polymers are ideal candidates to conjugate drugs because they show higher resistance to nonspecific protein adsorption in complex media than that of nonionic water-soluble polymers, such as poly(ethylene glycol). However, the charge balance characteristics of zwitterionic polymers used as NDVs will be broken from the inclusion of additional charged groups brought by conjugated drugs or functional groups, leading to the loss of resistance to protein adsorption. Consequently, the nonspecific protein adsorption on drug carriers will cause fast clearance from the blood system, an immune response, or even severe systemic toxicity. To overcome this drawback, a model zwitterionic polymer, poly(carboxybetaine methacrylate) (pCBMA), was modified by the introduction of a negatively charged component, to neutralize the positive charge provided by the model drug, doxorubicin (DOX). A DOX-conjugated NDV which possesses excellent resistance to nonspecific protein adsorption was achieved by the formation of a strongly hydrated pCBMA shell with a slightly negative surface charge. This kind of DOX-conjugated NDV exhibited reduced cytotoxicity and prolonged circulation time, and it accelerated DOX release under mild acid conditions. In tumor-bearing mouse studies a 55% tumor-inhibition rate was achieved without causing any body weight loss. These results indicate the importance of charge tuning in zwitterionic polymer-based NDVs.

Multifunctional polyampholyte hydrogels with fouling resistance and protein conjugation capacity.

Materials that are resistant to nonspecific protein adsorption are critical in the biomedical community. Specifically, nonfouling implantable biomaterials are necessary to reduce the undesirable, but natural foreign body response. The focus of this investigation is to demonstrate that polyampholyte hydrogels prepared with equimolar quantities of positively charged [2-(acryloyloxy)ethyl] trimethylammonium chloride (TMA) and negatively charged 2-carboxyethyl acrylate (CAA) monomers are a viable solution to this problem. TMA/CAA hydrogels were prepared and their physical and chemical properties were characterized. The fouling resistance of the TMA/CAA hydrogels were assessed at varying cross-linker densities using enzyme-linked immunosorbant assays (ELISAs). The results clearly demonstrate that TMA/CAA hydrogels are resistant to nonspecific protein adsorption. A unique advantage of the fouling resistant TMA/CAA system is that bioactive proteins can be covalently attached to these materials using standard conjugation chemistry. This was demonstrated in this study through a combination of ELISA investigations and short-term cell adhesion assays. The multifunctional properties of the TMA/CAA polyampholyte hydrogels shown in this work clearly demonstrate the potential for these materials for use as tissue regeneration scaffolds for many biomedical applications.