Bis(2-hydroxyethyl)terephthalate (BHET), polyethylene glycol (PEG) and hexamethylene diisocyanate (HMDI) are reacted together to synthesize polyurethane (PU). BHET is prepared by the glycolysis of polyethylene terephthalate (PET) waste. Insulin encapsulated with polyurethane-alginate nanoparticles is developed by crosslinking the sodium alginate with calcium chloride. X-ray diffraction (XRD) patterns of PU, calcium alginate (ALG) and crosslinked PU-ALG films demonstrate their amorphous nature. Fourier transform infrared (FT-IR) spectroscopy of the blend shows distinct characteristic peaks for both PU and alginate, indicating good dispersion of both the polymers. In this work, our aim was to develop a controlled oral release system for insulin and in this regard polyurethane-alginate nanoparticles (NPs) were formulated. The protective effect of the NPs for insulin delivery towards enzymatic degradation was determined during the in vitro release study at a pH of 1.2. PU-ALG NPs showed controlled release of insulin from these nanoparticles till the 8th hour in a phosphate buffer solution (pH 7.4 and pH 6.8). Variation of the blood glucose level in diabetic mice with different doses of insulin loaded mucoadhesive PU-ALG nanoparticles was observed. Diabetic mice showed a decrease in the blood glucose level and it returned to its initial level after the 13th hour; the calculated bioavailability is found to be sufficiently high (8.75%). © 2016 The Royal Society of Chemistry.

ROSHNARA MISRA

Physiology

A BHATTACHARYYA

D MUKHERJEE

P P KUNDU

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

RSC Advances

Chitosan (CS) and polyurethane-chitosan (PU-CS) nano-particles (NPs) were prepared for the core formation by complex coacervation method whereas alginate (ALG) and PU-ALG were crosslinked by ionic gelation method to form the protective shell-layer over the core. Effects of PU incorporation either within the core or shell or both were investigated by different in vitro and in vivo parameters. Fourier transform infrared (FTIR) spectroscopy of different compositions of nano-particles showed distinct characteristic peaks for CS, PU, and ALG, indicating their presence in variable ratios. Significance of polyurethane-incorporated systems towards insulin encapsulation efficiency, swelling parameters, insulin release, and in vivo pharmacological effect were also studied. Particle sizes, zeta potential, morphological analysis, mucoadhesion study, and in vivo acute toxicity studies of these core–shell nano-particles were also performed. Bioavailability of insulin ranged from 9.04% to 11.6% for polyurethane-incorporated chitosan-alginate core–shell nano-particle formulations which was significantly higher than the insulin bioavailability of basic CS/ALG core–shell nano-particle system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46365. © 2018 Wiley Periodicals, Inc.

Journal of Applied Polymer Science

Polyurethane-incorporated chitosan/alginate coreâ€“shell nano-particles for controlled oral insulin delivery

Waste polyethylene terephthalate (PET) is depolymerized through glycolysis and the glycolyzed product, bis (2-hydroxyethylene) terephthalate (BHET) is utilized in the synthesis of polyurethane as diol. Polyurethane (PU) is incorporated in a core- shell nanoparticle formulation along with alginate (ALG) and chitosan (CS) to develop an efficient oral insulin delivery vehicle. Fourier transform infrared (FT-IR) spectrums of the polyurethane-alginate/chitosan (PU-ALG/CS) nanoparticles confirm the presence of all elements distinctly. Nanoparticles of average particle size 90–110&nbsp;nm are clearly visible from the images of scanning electron microscope (SEM) and transmission electron microscope (TEM). Unique characteristics of insulin loaded PU-ALG/CS nanoparticles are noticed in both in vitro and in vivo studies. More than 90% insulin encapsulation efficiency, sustained swelling, controlled insulin release from mucoadhesive nanoparticle formulation are the major causes of long term hypoglycaemic effects in diabetic mice and improved insulin bioavailability (10.36%). PU-ALG/CS nanoparticles are also found to be safe, according to the acute toxicity studies. © 2017 Elsevier Ltd

European Polymer Journal

Preparation of polyurethaneâ€“alginate/chitosan core shell nanoparticles for the purpose of oral insulin delivery

Chitosan-alginate (CS/ALG) nanoparticles were prepared by formation of an ionotropic pre-gelation of an alginate (ALG) core entrapping insulin, followed by chitosan (CS) polyelectrolyte complexation, for successful oral insulin administration. Mild preparation process without harsh chemicals is aimed at improving insulin bio-efficiency in in vivo model. The nanoparticles showed an average particle size of 100-200. nm in dynamic light scattering (DLS), with almost spherical or sub-spherical shape and ~85% of insulin encapsulation. Again, retention of almost entire amount of encapsulated insulin in simulated gastric buffer followed by its sustained release in simulated intestinal condition proved its pH sensitivity in in vitro release studies. Significant hypoglycemic effects with improved insulin-relative bioavailability (~8.11%) in in vivo model revealed the efficacy of these core-shell nanoparticles of CS/ALG as an oral insulin carrier. No systemic toxicity was found after its peroral treatment, suggesting these core-shell nanoparticles as a promising device for potential oral insulin delivery. © 2014 Elsevier B.V.

International Journal of Biological Macromolecules

PH-sensitive chitosan/alginate core-shell nanoparticles for efficient and safe oral insulin delivery

With the aim of using poly(ethylene terephthalate) (PET) waste for the synthesis of a value added product, we prepared polyurethane (PU) from bishydrohxyethylene terephthalate (BHET), a byproduct obtained from the glycolysis of PET. Biodegradable, water-swelling PU was synthesized by the reaction of BHET, hexamethylene diisocyanate, and poly(ethylene glycol) (PEG). Both BHET and PU were characterized by Fourier transform infrared spectroscopy, and the formation of PU was further confirmed by NMR analysis. The swelling behavior of PU in water was examined in terms of the various molecular weights of PEG. Semi-interpenetrating network beads of PU and sodium alginate were prepared with calcium chloride (CaCl2) as a crosslinker to attain a pH sensitivity for successful oral protein/drug delivery. Bovine serum albumin (BSA) was used as a model protein. The pH-responsive swelling behavior and protein (BSA) release kinetics in different pH media corresponding to the gastrointestinal tract (pH 1.2 and 7.4) were investigated. The degree of swelling in the case of the PU-alginate beads at pH 1.2 was found to be at a minimum, whereas the degree of swelling was significantly elevated (1080%) at pH 7.4. This substantiated the pH sensitivity of the polymeric beads with a minimum loss of encapsulated protein in the stomach and the almost complete release of encapsulated protein in the intestine. This revealed good opportunities for oral protein/drug delivery with a polymer derived from waste PET. Moreover, the fungal biodegradation study confirmed its compatibility with the ecological system. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40650. Copyright © 2014 Wiley Periodicals, Inc.

Synthesis of a novel pH-sensitive polyurethane-alginate blend with poly(ethylene terephthalate) waste for the oral delivery of protein

pH sensitive PAA/S-chitosan hydrogel was prepared using ammonium persulfate (APS) as an initiator and methylenebisacrylamide (MBA) as a crosslinker for oral insulin delivery. The synthesized copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) study; morphology was observed under scanning electron microscope (SEM). The PAA/S-chitosan with ∼38% of insulin loading efficiency (LE) and ∼76% of insulin encapsulation efficiency (EE), showed excellent pH sensitivity, retaining ∼26% of encapsulated insulin in acidic stomach pH 1.2 and releasing of ∼98% of insulin in the intestine (pH 7.4), providing a prolonged attachment with the intestinal tissue. The oral administration of insulin loaded PAA/S-chitosan hydrogel was successful in lowering the blood glucose level of diabetic mice. The bioavailability of insulin was ∼4.43%. Furthermore, no lethality or toxicity was documented after its peroral administration. Thus, PAA/S-chitosan hydrogel could serve as a promising oral insulin carrier in future. © 2014 Elsevier Ltd.

Journal	Data powered by TypesetRSC Advances
Publisher	Data powered by TypesetRoyal Society of Chemistry
ISSN	2046-2069