Silver hydroxyapatite reinforced poly(vinyl alcohol)—starch cryogel nanocomposites and study of biodegradation, compressive strength and antibacterial activity

Abstract

In the present work polyvinyl alcohol‐starch/silver hydroxyapatite (PVA‐starch/AgHap) cryogel nanocomposites were prepared by successive freezing‐thawing of a blend of PVA and starch solutions to fabricate a cryogel followed by its reinforcement with silver hydroxyapatite (AgHap). The prepared macroporous cryogel nanocomposites were characterized by Infra‐red spectroscopy (FTIR), environmental scanning electron microscopy (ESEM), and particle size and charge analysis. The amylase induced enzymatic degradation of nanocomposites was studied gravimetrically in phosphate buffer saline (PBS) and effect of various parameters like chemical composition of the nanocomposite, number of freeze‐thaw cycles, and enzyme activity were assessed on the extent of degradation of the nanocomposite. The influence of chemical composition and experimental conditions like the number of freeze thaw cycles was studied on the elastic modulii of the cryogels. The in vitro cytotoxicity and antibacterial activity of nanocomposites was also evaluated against L‐529 fibroblast cells and gram positive and gram negative bacteria, respectively. POLYM. ENG. SCI., 59:254–263, 2019. © 2018 Society of Plastics Engineers

Influence of Hybrid Cellulose/Bentonite Fillers on Structure, Ambient, and Low Temperature Tensile Properties of Thermoplastic Starch Composites

“…Yet, its poor performance causes severe issues of water sensitivity, limited mechanical properties, and high fragility, over time . Its low mechanical properties are major concern, especially when exposed to hydrolytic, oxidative, low, and high temperature conditions . The organic nature of TPS, in terms of easy‐aging and degradation during usage and storage, is also to be considered in food packaging applications because it may result in the reduction of quality and lower shelf life of the TPS‐based products .…”

Physically Crosslinked Poly (Vinyl Alcohol)/Kappa-Carrageenan Hydrogels: Structure and Applications

“…Many polysaccharides, in their natural or chemically functionalized state, such as chitosan, starch, dextran, cellulose, xanthan, β-glucans, sodium alginate, carrageenans and so forth, have been previously blended with PVA to obtain cryogels [11,12]. Due to their overall hydrophilic character, the addition of polysaccharides (e.g., starch, hydroxyethyl starch) can increase the swelling degree of the blend cryogels up to 300% compared with neat PVA, submitted to identical physical crosslinking operational parameters [13,14]. Chitosan, starch and various glucans, for example, are reported to improve the hydrophilic character, elasticity and flexibility of the hydrogels for wound dressing applications, while also fine-tuning the diffusion coefficient of various active principles (antibiotics, nutraceuticals and so forth) through the polymeric matrix, from 10 −5 -10 −4 mm 2 /min with up to one order of magnitude [15,16].…”

“…For m t /m eq ≤ 0.5, Equation (11) permits the determination of the so-called "early-time" diffusion coefficient D e , while Equation (12), valid for m t /m eq > 0.6, permits the determination of the "late-time" diffusion coefficient, D l [73]. A complementary modeling method for the early-time approximation is the power-law approach introduced by Peppas and depicted in Equation (13), where k is a constant indicating the swelling rate and n denotes the type of transport mechanism. When n is equal to 0.5 (and according to some researchers ≤ 0.5), the transport rate of the solute into the hydrogel is Fickian, i.e., the solvent penetration rate is higher than the polymer chain relaxation rate (Equation (12) assumes a Fickian diffusion, i.e., n = 0.5 and k = 4 √ D e /δ √ π).…”

Design and Assessment of Biodegradable Macroporous Cryogels as Advanced Tissue Engineering and Drug Carrying Materials

“…Composite materials are made not by the simple blending (mixing) of two or more polymers but by incorporating another type of material, such as nano-, micro- or macroparticles [ 76 , 142 , 143 ]. The final material will have unique characteristics that can be beneficial for biomedical applications [ 69 , 144 , 145 ].…”

“…In vitro degradation is usually studied in a buffer or simulated biological media by analyzing the mass loss of the scaffold over time [ 48 , 85 , 151 ]. The simulated degradation conditions may involve chemical hydrolysis, such as in the case of PLLA scaffold [ 151 , 170 ], or induced by adding enzymes [ 69 ]. Temperature, pH and cryogel composition play a key role in the degradation profile.…”