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Biodegradable and Biocompatible Polymer Composite
Published in Sanjay Mavinkere Rangappa, Jyotishkumar Parameswaranpillai, Suchart Siengchin, Lothar Kroll, Lightweight Polymer Composite Structures, 2020
Naga Srilatha Cheekuramelli, Dattatraya Late, S. Kiran, Baijayantimala Garnaik
Although biodegradable composites are preferred to the biomedical applications, device failures are due to their extracellular influences and molecular interactions at the interfaces [51,52]. In general, series of tissue responses as well as the eliciting of non-specific protein adsorption are accompanied by denaturation and changes in protein conformation. Such kinds of protein changes participate during cell-signaling in the communication process and induce platelet adhesion, followed by blood clot and systemic inflammation [53]. Though biodegradable byproducts enabled toxicity effects, which induce complications in biomedical application. Overall, serve limitation alternatives experimented toward the end product application which could be a future solution for device failures, leading to efficient implantable applications [54].
Plastic Packaging for Parenteral Drug Delivery
Published in Sandeep Nema, John D. Ludwig, Parenteral Medications, 2019
Lloyd Waxman, Frances L. DeGrazio, Vinod D. Vilivalam
Protein adsorption to material surfaces is a complex process that depends on the interplay of three factors: the physicochemical characteristics of the protein itself, the properties of the adsorbing surface, and the liquid formulation (including buffers [pH] and excipients [sugars, polyols, amino acids, salts, and surfactants]). Other elements such as temperature and time of exposure will also have an impact. Since proteins are intrinsically surface active and tend to accumulate at interfaces, the formulation of hydrophobic therapeutic proteins, which are particularly susceptible to surface adsorption, can be particularly challenging [64]. Only in rare cases has an effort be made to alter the protein itself to reduce its adsorption either by covalent modification (e.g., pegylation, glycosylation) or by introducing changes in the amino acid sequence guided by a knowledge of the protein’s tertiary structure. Alternatively, the formulation can be modified with respect to pH and ionic strength or by the addition of suitable excipients such as surfactants and sugars. However, such alterations are constrained by the need to maintain both protein stability and an adequate biocompatibility. Another option is the selection of an appropriate container material for which the protein has low affinity.
Surface Modification of Polymer Biomaterials
Published in Yaser Dahman, Biomaterials Science and Technology, 2019
That being said, by eliciting specific protein adsorption to occur, the potential for specific cellular attachment and proliferation can be increased. Van Wachem et al. (1987) have shown a direct increase in human endothelial cell adhesion when surfaces were coated with specific proteins found in blood plasma. Polymers used as scaffolds for tissue growth, repair, and replacement require cellular growth and proliferation to occur in order to repair the damaged tissue. If the polymer scaffold does not allow for any protein adsorption, cellular adhesion would not occur and ultimately the device would fail. Therefore, protein adsorption is a difficult subject and one of great concern, because although indirect and undesired protein adsorption should be avoided to increase biocompatibility of the device, allowing specific and selective protein adsorption to occur will ultimately allow for certain devices to succeed.
Graphene oxide-reinforced pectin/chitosan polyelectrolyte complex scaffolds
Published in Journal of Biomaterials Science, Polymer Edition, 2021
P. R. Sivashankari, K. Krishna Kumar, M. Devendiran, M. Prabaharan
A scaffold with good swelling properties will hold physiological fluid when implanted in vivo and favor the adsorption of serum proteins by the scaffolds. Increased protein adsorption could improve cell adhesion, proliferation and ultimately the formation of 3D tissues. Therefore, adequate swelling is highly desired for the ideal scaffolds for tissue engineering applications. Figure 6(A) shows the in vitro swelling kinetics of PC and PCGO scaffolds as a function of time. It can be observed that all the scaffolds exhibited rapid swelling and reached the swelling equilibrium within 1 h due to the hydrophilic nature of chitosan, pectin and the GO. The PC, PCGO-1, PCGO-2 and PCGO-3 scaffolds exhibited a swelling degree of 1363%, 1622%, 2004% and 1581%, respectively, at the swelling equilibrium, which indicated that the swelling degree of PCGO scaffolds was increased with the increase in GO content up to 1 wt. % and then decreased with the further increase in GO content. The presence of an adequate number of pores (∼72%) and the improved hydrophilicity due to GO could be responsible for the increased swelling degree of PCGO-2 scaffolds. Whereas in the case of PCGO-3 scaffolds, the decrease in porosity (∼64%) and the rigid nature of pore walls could be the reason for its decreased swelling degree.
Porous aligned ZnSr-doped β-TCP/silk fibroin scaffolds using ice-templating method for bone tissue engineering applications
Published in Journal of Biomaterials Science, Polymer Edition, 2021
D. Bicho, R. F. Canadas, C. Gonçalves, S. Pina, R. L. Reis, J. M. Oliveira
The protein adsorption was also assessed (data not shown) because it denotes the first process that occurs after the scaffold implantation. This process changes the properties of the surface activating the immune system and inducing regeneration [63,64]. Unwanted protein adsorption may prevent cell-biomaterial interactions, so this process is strongly influenced by the composition of the surface of the biomaterial. The data disclosed in the present work indicate that the produced scaffolds adsorbed around 1.5 mg/mL of BSA in solution independently of the pore size, which represents about 43% (w/w) of the stock solution. It is important to have into consideration that scaffolds containing TCP were previously reported to promote absorption of serum protein resulting in cell adhesion and collagen secretion [65]. However, the impact of the produced scaffolds on protein adsorption also happens due to the presence of SF, since it was previously proven that SF induces protein adsorption either by hydrophobic and electrostatic interactions or covalent binding to the β-chain [66].
Protein triggered ordering transitions in poly (L-lysine)-coated liquid crystal emulsion droplets
Published in Liquid Crystals, 2019
Indu Verma, Sumyra Sidiq, Santanu Kumar Pal
In order to elucidate the protein-induced director configuration transition in PLL-modified LC droplets, three proteins: bovine serum albumin (BSA), concanavalin A (ConA) and cathepsin D (CathD) were studied which not only differ significantly in their respective electronegativities at physiological pH but also span a broad range of functions in biological systems [25–31]. We have chosen these three proteins because of their inherent anionic nature and hypothesised that possible formation of electrostatic complexes between PLL and those proteins may lead to an ordering transition of the LC at aqueous-LC interfaces. In this regard, the physiochemical properties such as isoelectric point (pI) of these proteins are relevant to predict the net charge on them at a particular pH (see Table 1). For example, at physiological pH (7.4), all proteins are negatively charged with BSA being most anionic followed by ConA and CathD, respectively, as confirmed by zeta potential measurements (Table 1). Thus, the zeta potential values at pH 7.4 are in good agreement with their respective pIs [25,30,31]. As PLL being positively charged, we, therefore, sought to understand the fundamental insight into the formation of charged complexes in the presence of these anionic proteins and how they couple to the ordering of the LC at those interfaces. In addition, keeping in mind the wide ranges of functions these proteins serve, it becomes essential to understand the mechanism of protein adsorption at polymeric surfaces for various biomedical applications.