High‐affinity water‐soluble system for efficient naringinase immobilization in polyvinyl alcohol–dimethyl sulfoxide lens‐shaped particles

Abstract

Polyvinyl alcohol (PVA) is a water-soluble, biocompatible and biodegradable synthetic polymer whose application in the immobilization of biological agents for use in biocatalysis has shown promising results. This study aimed to investigate and optimize the immobilization of naringinase from Penicillium decumbens in PVA networks, targeting for the hydrolysis of naringin. Variables such as the most suitable cross-linker, catalyst, inorganic salt, co-solvents and solidification process were identified as key issues for PVA-based methods to form lens-shaped particles, while retaining high enzyme activity and stability. Major improvements were established for better and more reproducible immobilization conditions, namely, by designing a new immobilization apparatus to produce uniform lens-shaped particles. The common problems of PVA-based entrapment were significantly mitigated, through the use of selected cross-linker, glutaraldehyde (GA), and co-solvent, dimethyl sulfoxide (DMSO), which decreased the toxicity of the immobilization process and allowed the control of membrane porosity, respectively. The relevance of DMSO and GA and their interaction and effect on the swelling ratio, encapsulation efficiency and residual activity of PVA biocatalysts were established. The immobilization of naringinase in PVA under a DMSO concentration of 60%, cross-linked with 1% GA, and particle lens size of 3.5-4.0 mm, width of 100-300 µm and average particle volume of 12.5 ± 0.92 µL, allowed an encapsulation efficiency of 98.6% and an average residual activity of 87% ± 3.6%. The kinetic characterization of the immobilized naringinase showed no changes in pH profile, whereas hydrolytic activity increased up to 60 °C. Immobilization in PVA/DMSO/GA lens-shaped particles enhanced the storage stability of naringinase. Moreover, these naringinase bio-immobilizates retained a conversion rate higher than 78% after 23 runs.

Formulation Development of Mucoadhesive Microparticle-Laden Gels for Oral Mucositis: An In Vitro and In Vivo Study

“…Although differences in the drug release profiles due to the type of PVA were not observed, the more rapid drug release from IM-NK(Dry) and IM-KP(Dry) than IM microparticles without PVA was observed. This was considered to be due to the wettability of IM microparticles by water being improved with PVA [ 32 , 33 ]. On the other hand, drug release from IM-NK(50) and IM-KP(50) was slower than from IM microparticles without PVA.…”

Thin poly(vinyl alcohol) cryogels: reactive groups, macropores and translucency in microtiter plate assays

“…Films of PVA cross-linked by GA were earlier proposed [26] and studied [27] as matrices for immobilization of biopolymers. However, pore volume, reactive group content and optical characteristics of these films have not been reported in the cited studies.…”

“…Transparent PVA films were also used as matrices for embedment of semiconductor nanocrystals [28] and enabled studies of the nanocrystal's absorption spectra. Large pores of thin PVA hydrogels synthesized under semi-frozen state create opportunities for biomolecule immobilization by covalent attachment to the pore walls instead of entrapment in the gel matrix [27]. Significant exposure of the biomolecules to the constituents of the permeant liquid may facilitate biorecognition phenomena such as immune complex formation described in Section 3.4.…”

Thermolysin entrapped in a gold nanoparticles/polymer composite for direct and sensitive conductometric biosensing of ochratoxin A in olive oil

“…Most of the studies carried out in view of the elaboration of electrochemical biosensors use conducting polymers such as polyaniline or polypyrrole [31] but composites based on polymer hydrogels incorporating conductive nanoparticles or nanostructures are of high interest for electrochemical biosensing applications [32]. Poly(vinyl alcohol) (PVA) is a nontoxic, hydrophilic and highly biocompatible synthetic polymer [33], with a high water content and minimal diffusion restrictions that provide the immobilized enzyme with a microenvironment close to that of the soluble one [34]. In the same way, polyethyleneimine (PEI) is a polycationic water soluble polymer bearing ionized amino groups able to interact with anionic groups located at proteins surface and constitutes a good matrix for enzyme stabilization [35].…”