Preparation, Characterization and Controlled Release Investigation of Biocompatible pH‐Sensitive PVA/PAA Hydrogels

Abstract

In the present research hydrogel films based on polyvinyl alcohol (PVA) and polyacrylic acid (PAA) blend, with various crosslink densities, have been prepared through different thermal treatment. The results of FTIR and DSC confirmed quality and quantity of conclusion on miscibility of PVA/PAA blends, respectively. Besides, biocompatibility of the samples has been proved in cytotoxicity tests using L929 cells, according to ISO10993–5. Water uptake of the hydrogel blends is measured. pH sensitivity properties of blends are studied with and without boiling in NaOH solutions where the effect of swelling in water before boiling has also been investigated. Preswellings in water and NaOH concentration have been found to be mainly effective on pH sensitivity of PVA/PAA blends. Biocompatibility and pH sensitivity behavior make these hydrogels appropriate candidates to orally deliver drugs such as insulin and peptides that can be released in basic pH of intestine. The stability of these films in acidic solutions and its expansion and also the consequent release of drugs in basic solutions have been studied by using Teofilin as a model drug by UV‐spectrophotometeric measurements.

Spatiotemporal Modification of Stimuli-Responsive Hyaluronic Acid/Poly(N-isopropylacrylamide) Hydrogels

“…Numerous biomaterials have used these stimuli to impart temporal changes to the material and chemical properties; however, significantly fewer examples exist of spatiotemporal 4 changes to the extent that the material respond to such stimuli. 21,22,23,24,25 Previous examples of spatiotemporal changes to stimuli response have typically removed the stimuli response. 22,26 For example, such spatiotemporal changes have been achieved by arresting the enzymatic degradation of materials by adding a non-enzymatically degradable crosslinker.…”

“…23,28,29,30,31 Many materials have used poly(N-isopropylacrylamide) (PNIPAM) as the thermally responsive polymer in their formulation as it has a lower critical solution temperature (LCST) around body temperature (32 °C). 25,32,33,34,35 Applications of thermally responsive PNIPAM-based hydrogels vary from temperature-responsive cell culture dishes to microlenses and bioactuators.…”

Development of potentially biocompatible hydrogels with cylindrical pores prepared from polyvinyl alcohol and low‐molecular weight polyacrylic acid

“…In this sense, several research works have employed polyvinyl alcohol (PVA) and polyacrylic acid (PAA) as the starting materials for pH‐sensitive hydrogels preparation . PVA is a hydrophilic, relatively inert, and ease‐to processing polymer , while PAA is not only a hydrophilic and biocompatible polymer, it also has a polyanionic structure whose pKa is found between 4.5 and 5.0 . It is widely accepted that in this kind of materials the repulsion interactions between ─COO − groups rise when pH increases, thus leading to increasing the swelling capability of the network .…”

Evaluation of the in vitro biodegradation and biological behavior of poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite composite microsphere-sintered scaffold for bone tissue engineering

“…The field of tissue engineering currently has opened new opportunities for regeneration of different organs, including bones. 1–17 Various biomaterials, composites, and approaches have been developed for this purpose. 18–21 The most common approach in bone tissue engineering is the implantation of osteoprogenitor cells onto three-dimensional (3D) scaffolds that physically support these bone cells.…”