Physicochemical characterisation of biosynthetic bacterial cellulose as a potential wound dressing material

The aim of this study was to characterise the physicochemical and biocompatibility properties of biosynthetic bacterial cellulose (BC) as a potential wound dressing material. The moisture content, water vapour transmission rate (WVTR), thermal stability, cyto- and haemo-compatibility of BC were investigated. Results indicated that the physicochemical properties of biosynthetic BC allow an optimum WVTR to be maintained for improved localised wound moisture levels, good thermal stability and excellent water imbibing capabilities. In vitro cytotoxicity and haemocompatibility confirmed the biocompatibility of BC and hence suitability of this material for further exploration into its’ application as a wound dressing material

Synthesis and structural characterization of bioactive PHA and γ-PGA oligomers for potential applications as a delivery system

The (trans)esterification reaction of bacterial biopolymers with a selected bioactive compound with a hydroxyl group was applied as a convenient method for obtaining conjugates of such compound. Tyrosol, a naturally occurring phenolic compound, was selected as a model of a bioactive compound with a hydroxyl group. Selected biodegradable polyester and polyamide, poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) and poly-γ-glutamic acid (γ-PGA), respectively, were used. The (trans)esterification reactions were carried out in melt mediated by 4-toluenesulfonic acid monohydrate. The structures of (trans)esterification products were established at the molecular level with the aid of ESI-MS2 (electrospray ionization tandem mass spectrometry) and/or 1H NMR (nuclear magnetic resonance) techniques. Performed analyses confirmed that the developed method leads to the formation of conjugates in which bioactive compounds are covalently bonded to biopolymer chains. The amount of covalently bonded bioactive compounds in the resulting conjugates depends on the type of biopolymers applied in synthesis

Forensic engineering of advanced polymeric materials Part IV: Case study of oxo-biodegradable polyethylene commercial bag – Aging in biotic and abiotic environment

This is an accepted manuscript of an article published by Elsevier in Waste Management on 03/04/2017, available online: https://doi.org/10.1016/j.wasman.2017.03.043 The accepted version of the publication may differ from the final published version.The public awareness of the quality of environment stimulates the endeavor to safe polymeric materials and their degradation products. The aim of the forensic engineering case study presented in this paper is to evaluate the aging process of commercial oxo-degradable polyethylene bag under real industrial composting conditions and in distilled water at 70 °C, for comparison. Partial degradation of the investigated material was monitored by changes in molecular weight, thermal properties and Keto Carbonyl Bond Index and Vinyl Bond Index, which were calculated from the FTIR spectra. The results indicate that such an oxo-degradable product offered in markets degrades slowly under industrial composting conditions. Even fragmentation is slow, and it is dubious that biological mineralization of this material would occur within a year under industrial composting conditions. The slow degradation and fragmentation is most likely due to partially crosslinking after long time of degradation, which results in the limitation of low molecular weight residues for assimilation. The work suggests that these materials should not be labeled as biodegradable, and should be further analyzed in order to avoid the spread of persistent artificial materials in nature

The synthesis and structural characterization of graft copolymers composed of γ-PGA backbone and oligoesters pendant chains

© 2017 The Authors. Published by American Chemical Society. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1021/jasms.8b05393The novel copolymers composed of poly-γ-glutamic acid (γ-PGA) and oligoesters have been developed. The structures of the obtained copolymers including variety of end groups were determined at the molecular level with the aid of electrospray ionization multistage mass spectrometry (ESI-MSn). The fragmentation experiment performed for the selected sodium adducts of the copolymers confirmed that the developed methods lead to the formation of graft copolymers composed of poly-γ-glutamic acid (γ-PGA) backbone and oligoesters pendant chains. Moreover, it was established that fragmentation of selected sodium adducts of graft copolymers proceeded via random breakage of amide bonds along the backbone and ester bonds of the oligoesters pendant chains. Considering potential applications of the synthesized copolymers in the area of biomaterials, the hydrolytic degradation under laboratory conditions and in vitro cytotoxicity tests were performed. The ESI-MSn technique applied in this study has been proven to be a useful tool in structural studies of novel graft copolymers as well as their degradation products.This work was supported by the Polish National Science Centre (Decision No DEC-2013/11/N/ST5/01364

Bioactive oligomers from natural polyhydroxyalkanoates and their synthetic analogues

Contemporary reports on the bioactive oligomers derived from natural aliphatic (co)polyesters (PHA) and their synthetic analogues, formed through anionic ring-opening polymerization (ROP) of β-substituted β-lactones are presented. Synthetic routes for such oligomers, developed mostly by Polish authors, are discussed. The described approaches enable design of novel biodegradable and bioactive oligomers for diverse applications in medicine, cosmetic industry and agrochemistry. Abstrakt: Przedstawiono przegląd aktualnych wyników badań dotyczących bioaktywnych oligomerów otrzymywanych z naturalnych alifatycznych (ko)poliestrów (PHA) oraz ich syntetycznych analogów, uzyskanych na drodze anionowej polimeryzacji z otwarciem pierścienia (ROP) β-podstawionych β-laktonów. Omówiono ścieżki syntezy tych oligomerów opracowane głównie przez polskich badaczy. Zaprezentowane metody umożliwiają projektowanie nowych biodegradowalnych a zarazem bioaktywnych oligomerów dla różnorodnych zastosowań w medycynie, przemyśle kosmetyczny i agrochemii

From anionic ring-opening polymerization of β-butyrolactone to biodegradable poly(hydroxyalkanoate)s: Our contributions in this field

© 2021 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/polym13244365The feasibility of synthesis of functionalized poly(3-hydroxybutanoic acid) analogue and its copolymers via ring-opening polymerization of β-butyrolactone mediated by activated anionic initiators is presented. Using these new synthetic approaches, polyesters with a defined chemical structure of the end groups, as well as block, graft, and random copolymers, have been obtained and characterized by modern instrumental techniques, with special emphasis on ESI-MS. The relationship between the structure and properties of the prepared polymeric materials is also discussed.This research is partly supported by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement, No. 872152, project GREEN-MAP.Published onlin

Bacterial-derived Polymer Poly-y-Glutamic Acid (y-PGA)-based micro/nanoparticles as a delivery system for antimicrobials and other biomedical applications

Abstract: In the past decade, poly-γ-glutamic acid (γ-PGA)-based micro/nanoparticles have garnered remarkable attention as antimicrobial agents and for drug delivery, owing to their controlled and sustained-release properties, low toxicity, as well as biocompatibility with tissue and cells. γ-PGA is a naturally occurring biopolymer produced by several gram-positive bacteria that, due to its biodegradable, non-toxic and non-immunogenic properties, has been used successfully in the medical, food and wastewater industries. Moreover, its carboxylic group on the side chains can offer an attachment point to conjugate antimicrobial and various therapeutic agents, or to chemically modify the solubility of the biopolymer. The unique characteristics of γ-PGA have a promising future for medical and pharmaceutical applications. In the present review, the structure, properties and micro/nanoparticle preparation methods of γ-PGA and its derivatives are covered. Also, we have highlighted the impact of micro/nanoencapsulation or immobilisation of antimicrobial agents and various disease-related drugs on biodegradable γ-PGA micro/nanoparticles.Iraqi cultural attach

Polymeric carriers for delivery systems in biomedical applications—In memory of Professor Andrzej Dworak

© 2023 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/polym15081810Published onlin

Biomass extraction using non-chlorinated solvents for biocompatibility improvement of polyhydroxyalkanoates

An economically viable method to extract polyhydroxyalkanoates (PHAs) from cells is desirable for this biodegradable polymer of potential biomedical applications. In this work, two non-chlorinated solvents, cyclohexanone and -butyrolactone, were examined for extracting PHA produced by the bacterial strain Cupriavidus necator H16 cultivated on vegetable oil as a sole carbon source. The PHA produced was determined as a poly(3-hydroxybutyrate) (PHB) homopolyester. The extraction kinetics of the two solvents was determined using gel permeation chromatography (GPC). When cyclohexanone was used as the extraction solvent at 120 C in 3 min, 95% of the PHB was recovered from the cells with a similar purity to that extracted using chloroform. With a decrease in temperature, the recovery yield decreased. At the same temperatures, the recovery yield of -butyrolactone was significantly lower. The effect of the two solvents on the quality of the extracted PHB was also examined using GPC and elemental analysis. The molar mass and dispersity of the obtained polymer were similar to that extracted using chloroform, while the nitrogen content of the PHB extracted using the two new solvents was slightly higher. In a nutshell, cyclohexanone in particular was identified as an expedient candidate to efficiently drive novel, sustainable PHA extraction processes

Recent advances and applications of bacterial cellulose in biomedicine

© 2021 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/polym13030412Bacterial cellulose (BC) is an extracellular polymer produced by Komagateibacter xylinus, which has been shown to possess a multitude of properties, which makes it innately useful as a next-generation biopolymer. The structure of BC is comprised of glucose monomer units polymerised by cellulose synthase in β-1-4 glucan chains which form uniaxially orientated BC fibril bundles which measure 3–8 nm in diameter. BC is chemically identical to vegetal cellulose. However, when BC is compared with other natural or synthetic analogues, it shows a much higher performance in biomedical applications, potable treatment, nano-filters and functional applications. The main reason for this superiority is due to the high level of chemical purity, nano-fibrillar matrix and crystallinity. Upon using BC as a carrier or scaffold with other materials, unique and novel characteristics can be observed, which are all relatable to the features of BC. These properties, which include high tensile strength, high water holding capabilities and microfibrillar matrices, coupled with the overall physicochemical assets of bacterial cellulose makes it an ideal candidate for further scientific research into biopolymer development. This review thoroughly explores several areas in which BC is being investigated, ranging from biomedical applications to electronic applications, with a focus on the use as a next-generation wound dressing. The purpose of this review is to consolidate and discuss the most recent advancements in the applications of bacterial cellulose, primarily in biomedicine, but also in biotechnology.Published onlin