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Planar chromatography is used to develop methods for the analytical control of processes of the synthesis of biomedical polymers and their complexes with biologically active substances, which made it possible to create a number of long-acting antiviral, antitumor, antimicrobial, and antiseptic preparations. [ABSTRACT FROM AUTHOR]

To analyze the substantial development of biomedical polymers in a number of potential biomedical domains, including the disease diagnosis and therapy. Results. The relationship between material's properties and functions for matching biomedical applications is thoroughly elucidated in this paper, along with a rundown of current advancements in the production and appliance of biomedical polymers. The peptide, biomembrane, microbe and cell-based biomedical polymers are presented and highlighted as new biomaterials for the tumor precision treatment. Additionally, the prospects and difficulties of creating the future biomedical polymers, which are healthier, safer, and more effective, are appraised. Conclusions. This systematic and in-depth analysis of the most recent advancements in the biomedical polymers development is intended to inspire and promote new discoveries in the basic science and clinical application. [ABSTRACT FROM AUTHOR]

An analysis of literature data on the set of reactions for the production of macromolecules with a high content of phosphorus and sulfur has been carried out, and basic approaches that allow the introduction of these elements into the composition of polymers and polymeric materials have been considered in compliance with the fundamental principles of green chemistry. Methods for synthesis of functional polymers under mild conditions that require minimal energy input from external sources, which can become new growth points for green industrial technologies, are considered. Particular attention focuses on the synthesis of polyphosphazenes and polyphosphoesters for biomedical purposes, as well as on the inverse vulcanization reaction to give polymers used in sorption wastewater treatment, the creation of current sources, and IR optics. [ABSTRACT FROM AUTHOR]

Asthma is a chronic airway inflammatory disease with complex mechanisms, and these patients often encounter difficulties in their treatment course due to the heterogeneity of the disease. Currently, clinical treatments for asthma are mainly based on glucocorticoid-based combination drug therapy; however, glucocorticoid resistance and multiple side effects, as well as the occurrence of poor drug delivery, require the development of more promising treatments. Nanotechnology is an emerging technology that has been extensively researched in the medical field. Several studies have shown that drug delivery systems could significantly improve the targeting, reduce toxicity and improve the bioavailability of drugs. The use of multiple nanoparticle delivery strategies could improve the therapeutic efficacy of drugs compared to traditional delivery methods. Herein, the authors presented the mechanisms of asthma development and current therapeutic methods. Furthermore, the design and synthesis of different types of nanomaterials and micromaterials for asthma therapy are reviewed, including polymetric nanomaterials, solid lipid nanomaterials, cell membranes-based nanomaterials, and metal nanomaterials. Finally, the challenges and future perspectives of these nanomaterials are discussed to provide guidance for further research directions and hopefully promote the clinical application of nanotherapeutics in asthma treatment. [ABSTRACT FROM AUTHOR]

In recent years, the environmental problems accompanying the extensive application of biomedical polymer materials produced from fossil fuels have attracted more and more attentions. As many biomedical polymer products are disposable, their life cycle is relatively short. Most of the used or overdue biomedical polymer products need to be burned after destruction, which increases the emission of carbon dioxide (CO2). Developing biomedical products based on CO2 fixation derived polymers with reproducible sources, and gradually replacing their unsustainable fossil-based counterparts, will promote the recycling of CO2 in this field and do good to control the greenhouse effect. Unfortunately, most of the existing polymer materials from renewable raw materials have some property shortages, which make them unable to meet the gradually improved quality and property requirements of biomedical products. In order to overcome these shortages, much time and effort has been dedicated to applying nanotechnology in this field. The present paper reviews recent advances in nanocomposites of CO2 fixation derived reproducible polymers for biomedical applications, and several promising strategies for further research directions in this field are highlighted.

A plethora of synthetic, hybrid and biological polymers are widely being used in medical applications. Many polymers are helpful in our civic activities. Their peculiar chemical, physical, and biological properties are applicable in multiple domains of life from engineering to medicine. This review specifically addresses the novel polymers and their applications in clinical medicine. It has been reported by the researchers that, synthetic polymers are not only playing tremendous roles in micro and macro medical-industry but these also play a remarkable role at nano levels as nano-drug carriers in pharmaceuticals. In this review, we will give a brief introduction of polymers and how they are widely being used in medicinal interventions. We will further shed light on the future prospects of polymers with an updated version. [ABSTRACT FROM AUTHOR]

In this work, new polymers were synthesized by condensation polymerization and reacted with sulfonail amide to get drug polymers (poly ester amide) at 90C°using mixture of DMF & dioxane (1:1). Synthetic biomedical polymers and their derivatives are frequently utilised in medical and pharmaceutical purposes. Recently, Specific consideration has been showed to chemical features of biocompatible polymers, since these polymers have an benefit of being quickly hydrolyzed into easy get rid of and non-toxic results which can be subsequently removed via metabolic pathways. The new polymer which has bioactive group's moiety were determined physical features by FTIR & UV techniques. In addition to its biochemical properties. [ABSTRACT FROM AUTHOR]

Asthma is a chronic airway inflammatory disease with complex mechanisms, and these patients often encounter difficulties in their treatment course due to the heterogeneity of the disease. Currently, clinical treatments for asthma are mainly based on glucocorticoid-based combination drug therapy; however, glucocorticoid resistance and multiple side effects, as well as the occurrence of poor drug delivery, require the development of more promising treatments. Nanotechnology is an emerging technology that has been extensively researched in the medical field. Several studies have shown that drug delivery systems could significantly improve the targeting, reduce toxicity and improve the bioavailability of drugs. The use of multiple nanoparticle delivery strategies could improve the therapeutic efficacy of drugs compared to traditional delivery methods. Herein, the authors presented the mechanisms of asthma development and current therapeutic methods. Furthermore, the design and synthesis of different types of nanomaterials and micromaterials for asthma therapy are reviewed, including polymetric nanomaterials, solid lipid nanomaterials, cell membranes-based nanomaterials, and metal nanomaterials. Finally, the challenges and future perspectives of these nanomaterials are discussed to provide guidance for further research directions and hopefully promote the clinical application of nanotherapeutics in asthma treatment.

Liver metastases arising from colorectal cancer (CRC) are a major challenge for cancer treatment, as they often emerge as unresectable and resistant to therapy. Novel treatments targeting the specific metastatic tumor microenvironment (TME) may improve the therapeutic outcome. One relevant receptor at the TME in the liver is the endothelial-expressed cell adhesion molecule E-selectin. In this study, we showed in a mouse model of aggressive CT26-derived liver metastasis, that the delivery of otherwise non-effective Doxorubicin via an E-selectin-targeted polymer-peptide-drug conjugate reduced tumor burden of liver metastases and significantly prolonged survival, with ∼50% of mice being tumor-free. In contrast to B16-derived lung metastases, which can successfully be prevented by a "drug-free" E-selectin-blocking copolymer, neither E-selectin-blocking pre-treatment nor the combination with targeted Doxorubicin-delivery proved beneficial against CT26 liver metastasis. In-depth inquiry revealed that E-selectin-blockade by the "drug-free" copolymer reduced E-selectin expression in metastatic livers, but did not prevent CT26 liver colonization, and increased the prevalence of B-cells, possibly indicating an ambiguous role of these cells. However, it did not significantly alter leukocyte migration into the malignant tissue. Overall, targeting E-selectin with nanomedicines is a highly efficient strategy to treat established liver metastases, while the benefit of E-selectin blockade by itself may depend on tumor type and TME-specific factors. [Display omitted] • Colorectal cancer liver metastases of mice regressed upon a single treatment with E-selectin-targeted polymer-drug conjugate. • Overall, 50% of the P-Esbp-Dox treated mice survived with no disease recurrence. • E-selectin blocking copolymer reduced E-selectin expression in metastatic livers but did not affect metastatic growth. • E-selectin is a viable target for drug delivery, but its blockade may have ambiguous effects at the TME. [ABSTRACT FROM AUTHOR]

Diabetic chronic wounds cause a significant amount of pain to patients because of their low cure rates and high recurrence rates. Traditional approaches to treating diabetic chronic wounds often involve the delivery of drugs or cytokines that regulate the microenvironment and eliminate bacterial infection in the wound area, but they are passive in controlling cell behaviors and may lead to drug resistance. Emerging drug-free wound treatments are important for convenient, effective, and safe treatment strategies. However, the current approaches cannot fully promote tissue regeneration or prevent bacterial infections. Here, the efficacy of a negatively charged fiber dressing in promoting diabetic chronic wound healing is investigated. The negatively charged fiber dressing can generate reactive oxygen species to inhibit bacterial reproduction with the assistance of ultrasound during the inflammatory phase. Furthermore, the dressing provides an electrostatic field that regulates cellular behavior during the inflammatory and proliferative phases. In particular, the dressing can promote fibroblast migration and induce macrophage polarization and neovascularization without any additional drugs. It is demonstrated that this strategy enables the healing of diabetic chronic wounds in a mouse model, achieving effective wound closure over a 12-day treatment cycle and providing a drug-free therapeutic strategy for diabetic chronic wound care., (© 2023 Wiley-VCH GmbH.)

Abstract Recently, growing interest in polymers (natural and synthetic) as drug carriers in controlled release formulations and drug targeting systems that may improve the efficacy of treatment and reduce the side effects of a drug therapy, has been observed. Special attention has been paid to improving the effectiveness of antibiotics, which constitute a very important, often life-saving group of drugs. In this paper, we review polymers as macromolecular carriers of fluoroquinolones, a group of antibiotics with a broad spectrum of activity. We consider both physical intermixtures and chemical conjugates, although we discuss in greater depth the latter type of coupling, in which covalent bonds between drug molecules and polymers occur. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the surface properties of polymeric composites and the osteoblastic cell behaviour set in direct contact with the biomaterials tested. The surface properties were evaluated before and after 6-month incubation in an in vitro environment. The composite materials were prepared by means of extrusion and injection moulding. Three commercially available thermoplastic polymers (ABS (poly)acrylonitrile butadiene styrene) were used as composite matrices. Antibacterial silver nanoparticles (AgNPs) were added as a modifying phase. Surface properties of the materials tested, such as: wettability, roughness and microstructure, were determined. Furthermore the morphology of Saos-2 human osteoblastic cells in direct contact with the composite materials was assessed after the 7-day culture. The addition of silver nanoparticles caused minor changes in the wettability and roughness values. As light modification, the silver nanoparticles influenced the microstructure. The osteoblasts displayed the proper morphology and they evenly settled on the surface of the pure polymer and composite materials, which indicated the material cytocompatibility. [ABSTRACT FROM AUTHOR]

Polylactide (PLA) represents one of the most promising biomedical polymers due to its biodegradability, bioresorbability and good biocompatibility. This work highlights the synthesis and characterization of PLAs using novel diethylzinc/gallic acid (ZnEt2/GAc) and diethylzinc/propyl gallate (ZnEt2/PGAc) catalytic systems that are safe for human body. The results of the ring-opening polymerization (ROP) of rac-lactide (rac-LA) in the presence of zinc-based catalytic systems have shown that, depending on the reaction conditions, “predominantly isotactic”, disyndiotactic or atactic PLA can be obtained. Therefore, the controlled and stereoselective ROP of rac-LA is discussed in detail in this paper.

We aimed to study the distribution of hydroxyapatite (HA) and halloysite nanotubes (HNTs) as fillers and their influence on the hydrophobic character of conventional polymers used in the biomedical field. The hydrophobic polyester poly (ε-caprolactone) (PCL) was blended with its more hydrophilic counterpart poly (lactic acid) (PLA) and the hydrophilic acrylate poly (2-hydroxyethyl methacrylate) (PHEMA) was analogously compared to poly (ethyl methacrylate) (PEMA) and its copolymer. The addition of HA and HNTs clearly improve surface wettability in neat samples (PCL and PHEMA), but not that of the corresponding binary blends. Energy-dispersive X-ray spectroscopy mapping analyses show a homogenous distribution of HA with appropriate Ca/P ratios between 1.3 and 2, even on samples that were incubated for seven days in simulated body fluid, with the exception of PHEMA, which is excessively hydrophilic to promote the deposition of salts on its surface. HNTs promote large aggregates on more hydrophilic polymers. The degradation process of the biodegradable polyester PCL blended with PLA, and the addition of HA and HNTs, provide hydrophilic units and decrease the overall crystallinity of PCL. Consequently, after 12 weeks of incubation in phosphate buffered saline the mass loss increases up to 48% and mechanical properties decrease above 60% compared with the PCL/PLA blend.

Biodegradable polyesters gain significant attention because of their wide potential biomedical applications. The ring-opening polymerization method is widely used to obtain such polymers, due to high yields and advantageous properties of the obtained material. The preparation of new, effective, and bio-safe catalytic systems for the synthesis of biomedical polymers is one of the main directions of the research in modern medical chemistry. The new diethylzinc/propyl gallate catalytic system was first used in the copolymerization of ε-caprolactone and rac-lactide. In this paper, the activity of the new zinc-based catalytic system in the copolymerization of cyclic esters depending on the reaction conditions was described. The microstructure analysis of the obtained copolyesters and their toxicity studies were performed. Resulted copolyesters were characterized by low toxicity, moderate dispersity (1.19−1.71), varying randomness degree (0.18−0.83), and average molar mass (5300−9800 Da).

A novel series of α-aminophosphonates containing chitosan moiety was obtained in high yields from reactions of chitosan with aromatic aldehydes and triphenylphosphite in the presence of lithium perchlorate as a catalyst. The structures of the synthesized compounds were confirmed by IR and 1H NMR spectral data. Compounds (1–4) showed high antimicrobial activities against Escherichia coli (NCIM2065), Serratia marcescens, Enterobacter cloacae, Shigella dysenteriae, Salmonella enterica and Proteus vulgaris as Gram-negative bacteria, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria and Candida albicans as a fungus, at low concentrations (2.5–10 mg/mL).

Polycaprolactone (PCL) is a biodegradable synthetic polymer that is currently widely used in many pharmaceutical and medical applications. In this paper we describe the coordination ring-opening polymerization of ε-caprolactone in the presence of two newly synthesized catalytic systems: diethylzinc/gallic acid and diethylzinc/propyl gallate. The chemical structures of the obtained PCLs were characterized by 1H- or 13C-NMR, FTIR spectroscopy and MALDI TOF mass spectrometry. The average molecular weight of the resulting polyesters was analysed by gel permeation chromatography and a viscosity method. The effects of temperature, reaction time and type of catalytic system on the polymerization process were examined. Linear PCLs with defined average molecular weight were successfully obtained. Importantly, in some cases the presence of macrocyclic products was not observed during the polymerization process. This study provides an effective method for the synthesis of biodegradable polyesters for medical and pharmaceutical applications due to the fact that gallic acid/propyl gallate are commonly used in the pharmaceutical industry.

Biodegradable or bioresorbable polymers are commonly used in various pharmaceutical fields (e.g., as drug delivery systems, therapeutic systems or macromolecular drug conjugates). Polyesters are an important class of polymers widely utilized in pharmacy due to their biodegradability and biocompatibility features. In recent years, there has been increased interest in enzyme-catalyzed ring-opening polymerization (e-ROP) of cyclic esters as an alternative method of preparation of biodegradable or bioresorbable polymers. Ionic liquids (ILs) have been presented as green solvents in enzymatic ring-opening polymerization. The activity, stability, selectivity of enzymes in ILs and the ability to catalyze polyester synthesis under these conditions are discussed. Overall, the review demonstrates that e-ROP of lactones or lactides could be an effective method for the synthesis of useful biomedical polymers.

The past decade has seen growing interest in the investigation of peptides with antimicrobial activity (AMPs). One approach utilized in infection control is incorporation of antimicrobial agents conjugated with the polymers. This review presents the recent developments on polymeric AMP carriers and their potential applications in the biomedical and pharmaceutical fields.

To evaluate the effects of ionic liquids (ILs) on the microstructural features of aliphatic polyesters for biomedical applications, a series of copolymers were synthesized by lipase ring opening polymerization of rac-lactide (rac-LA) and "-caprolactone (CL). The chemical structures of resulting polymers were characterized by 1H- and 13C-NMR and the average molecular weight (Mn) and dispersity index were characterized by gel permeation chromatography. The structure of the copolymers confirms the presence of linear polymer chains with end-functional hydroxyl groups allowing covalent coupling of the therapeutic agents. Chain microstructure of copolymers indicates the presence of both random and block copolymers depending on the synthesis conditions. Moreover, it was found that CL is the most active co-monomer during copolymerization which enhances the polymerizability of rac-LA and allows to obtain higher Mn of the copolymers. The results demonstrate that ILs could be promising solvents in synthesis of aliphatic esters for biomedical applications. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to develop the perspective biodegradable poly(ester-urethane) (PUR) carriers based on 'predominantly isotactic' and atactic polylactides (PLAs), and poly(ε-caprolactone) (PCL), for the controlled release of epirubicin (EPI). Methods: The biodegradable PURs containing different soft segments as new and effective carriers of EPI have been obtained. The preliminary studies on toxicity and degradation of obtained polymers, and the release of the EPI from PUR carriers were carried out. Results: We found that the kinetic release of EPI from the obtained PUR carriers tested in vitro at 37°C and pH 7.4 was strongly dependent on the kind of the polyesters, used as the soft segment in PURs synthesis. Furthermore, we demonstrated that the EPI was released from various synthesized carriers in a rather regular manner, according to the diffusion-degradation and degradation mechanisms. Importantly, in some cases, the kinetics of the EPI release was nearly zero-order. Conclusion: The results show that the obtained PURs are very effective and perspective carriers and might be potentially applied in the technology of high controlled EPI delivery systems. [ABSTRACT FROM AUTHOR]

Physical-chemical, morphological and physical-mechanical characterization was made for cellulose nonwoven modified with chitosan nanoparticles with a view to their possible use in medicine as gynecological tampons. It was an aim of the work to assess the impact of the addition of chitosan nanoparticles upon the biological activity and toxicity of the materials prepared. Methodology was prepared for the examination of the gynecological devices in the range of their useful properties, notably the mechanical strength, surface density and absorption. Aqueous extracts were examined after an extraction process that simulated standard use of the medical device, and after a surplus extraction. The content of water-soluble-, surfactant- and reductive substances was estimated as well as the contents of heavy metals like cadmium, lead, zinc and mercury by the ASA method. Morphology examination permitted to assess the impact of the extraction processes on the fibre structure. Antibacterial activity against Escherichia coli and Staphylococcus aureus, and antifungal activity against Candida albicans was measured. Altogether examinations were made to assess whether the cellulosic nonwoven modified with chitosan nanoparticles meets the demands of medical devices and lends itself to the manufacture of tampons. [ABSTRACT FROM AUTHOR]

Dense CO2 can be used as an environmentally-benign polymer processing medium because of its liquid-like densities and gas-like mass transfer properties.In this work, polymer bio-blends of polycarbonate (PC), a biocompatible polymer, and polycaprolactone (PCL), a biodegradable polymer were prepared. Dense CO2 was used as a reaction medium for the melt-phase PC polymerization in the presence of dense CO2-swollen PCL particles and this method was used to prepare porous PC/PCL blends. To extend the applicability of dense CO2 to the biomedical industry and polymer blend processing, the impregnation of ibuprofen into the blend was conducted and subsequent dissolution characteristics were observed.

The solubility parameter seems to be a useful tool for thermodynamic characterisation of different materials. The solubility parameter concept can be used to predict sufficient miscibility or solubility between a solvent and a polymer, as well as components of co-polymer matrix in composite biomaterials. The values of solubility parameter were determined for polycaprolactone (PCL), polylactic acid (PLA) and polyethylene glycol (PEG) by using different procedures and experimental data, collected by means of inverse gas chromatography. [ABSTRACT FROM AUTHOR]

Poly (glycerol adipate) (PGA) can be produced from divinyl adipate and unprotected glycerol by an enzymatic route to generate a polymer with relatively low molar mass (12 kDa). PGA bears a pendant hydroxyl group which imparts a hydrophilic character to this water insoluble polymer. We have examined the effect of synthesis temperature on polymer characteristics through various techniques including FT-IR, 1 H and 13 C NMR, surface and thermal analysis, both to expand the data already present in the literature about this material and to understand better its properties for potential pharmaceutical applications. The use of a lipase (Novozym 435) as a catalyst suppresses cross-linking at the pendant glyceryl hydroxyl through steric hindrance at the active site, thus producing polymers with low degrees of branching (5–30%), and removes the need for any pre- or post-polymerization protection/deprotection reactions. Careful temperature control during synthesis can give polymers with reproducible molecular weights and reduced amounts of polymer branching compared to synthesis at higher temperatures. Due to the ability of the synthetic route to produce a range of structures, PGA generated by enzymatic routes may emerge as a useful biodegradable polymer platform to engineer solid dispersions or nanoparticles for healthcare applications. [ABSTRACT FROM AUTHOR]

Polylactide (PLA) represents one of the most promising biomedical polymers due to its biodegradability, bioresorbability and good biocompatibility. This work highlights the synthesis and characterization of PLAs using novel diethylzinc/gallic acid (ZnEt2/GAc) and diethylzinc/propyl gallate (ZnEt2/PGAc) catalytic systems that are safe for human body. The results of the ring-opening polymerization (ROP) of rac-lactide (rac-LA) in the presence of zinc-based catalytic systems have shown that, depending on the reaction conditions, "predominantly isotactic", disyndiotactic or atactic PLA can be obtained. Therefore, the controlled and stereoselective ROP of rac-LA is discussed in detail in this paper. [ABSTRACT FROM AUTHOR]

Fibres prepared on an experimental scale from biodegradable copolyester of glycolide and lactide (PLGA) and from PLGA with the addition of 9% of atactic poly([R,S]-3-hydroxybutyrate (PLGA+a-PHB) were characterised to assess their possible use in the preparation of surgery sutures. Commercial spinfinish Estesol PF 790 (Bozzetto Group, Italy) was applied on the fibres in the spinning step. A method was prepared for an organic extraction of the spinfinish from the PLGA fibres, and the process efficacy was assessed by scanning electron microscopy (SEM) and by estimating chemical purity. With spinfinish removed, the fibres were subjected to an extraction process which simulated the utilisation of the products in an aqueous medium. The aqueous extracts were analysed to estimate contamination contents. Also estimated was the time in which the fibres degrade when subjected to surplus extraction in an aqueous medium. [ABSTRACT FROM AUTHOR]

A novel series of α-aminophosphonates containing chitosan moiety was obtained in high yields from reactions of chitosan with aromatic aldehydes and triphenylphosphite in the presence of lithium perchlorate as a catalyst. The structures of the synthesized compounds were confirmed by IR and 1 H NMR spectral data. Compounds ( 1 – 4 ) showed high antimicrobial activities against Escherichia coli (NCIM2065), Serratia marcescens , Enterobacter cloacae , Shigella dysenteriae , Salmonella enterica and Proteus vulgaris as Gram-negative bacteria, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria and Candida albicans as a fungus, at low concentrations (2.5–10 mg/mL). [ABSTRACT FROM AUTHOR]

Polycaprolactone (PCL) is a biodegradable synthetic polymer that is currently widely used in many pharmaceutical and medical applications. In this paper we describe the coordination ring-opening polymerization of e-caprolactone in the presence of two newly synthesized catalytic systems: diethylzinc/gallic acid and diethylzinc/propyl gallate. The chemical structures of the obtained PCLs were characterized by 1H- or 13C-NMR, FTIR spectroscopy and MALDI TOF mass spectrometry. The average molecular weight of the resulting polyesters was analysed by gel permeation chromatography and a viscosity method. The effects of temperature, reaction time and type of catalytic system on the polymerization process were examined. Linear PCLs with defined average molecular weight were successfully obtained. Importantly, in some cases the presence of macrocyclic products was not observed during the polymerization process. This study provides an effective method for the synthesis of biodegradable polyesters for medical and pharmaceutical applications due to the fact that gallic acid/propyl gallate are commonly used in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Biodegradable polyurethane elastomers (BioEPUR) are becoming increasingly important as biomaterials because they have excellent chemical, physico-mechanical and biological properties. This review presents the recent developments on BioEPUR and their potential applications in the biomedical and pharmaceutical fields. The aim of this work is to present an overview of the various methods of synthesis and properties of biomedical BioEPUR. Polyurethanes-based aliphatic or cycloaliphatic diisocyanates and polyesters, poly(ester-carbonate)s or copolymers of heterocyclic monomers were discussed. [ABSTRACT FROM AUTHOR]

Biodegradable or bioresorbable polymers are commonly used in various pharmaceutical fields (e.g., as drug delivery systems, therapeutic systems or macromolecular drug conjugates). Polyesters are an important class of polymers widely utilized in pharmacy due to their biodegradability and biocompatibility features. In recent years, there has been increased interest in enzyme-catalyzed ring-opening polymerization (e-ROP) of cyclic esters as an alternative method of preparation of biodegradable or bioresorbable polymers. Ionic liquids (ILs) have been presented as green solvents in enzymatic ring-opening polymerization. The activity, stability, selectivity of enzymes in ILs and the ability to catalyze polyester synthesis under these conditions are discussed. Overall, the review demonstrates that e-ROP of lactones or lactides could be an effective method for the synthesis of useful biomedical polymers. [ABSTRACT FROM AUTHOR]

Porous polyurethane-urea substrates for bone tissue cultures were fabricated using two types of polyols: rapeseed oil-based and poly(ε-caprolactone)diol in various weight ratios. The materials were produced using hexamethylene diisocyanate, distilled water as a chain extender and sodium chloride particles as porogens. Polyurethane synthesis was performed using a prepolymer method in mass. Scanning electron microscopy was used to examine the porosity and differences in structure according to the various compositions of the reaction mixtures. Thermal degradation analysis was performed using thermogravimetric analysis techniques, and differential scanning calorimetry was used to determine phase-transition temperatures and thermal effects. Chemical composition and degree of phase separation of polyurethane-urea materials were examined by IR absorption spectroscopy. The bioactivity and degradation of synthesised materials were studied through testing in simulated body fluid. The obtained results lead to the conclusion that the polyurethane-urea materials based on rapeseed oil are very promising substrates for bone tissue cultures. [ABSTRACT FROM AUTHOR]

The past decade has seen growing interest in the investigation of peptides with antimicrobial activity (AMPs). One approach utilized in infection control is incorporation of antimicrobial agents conjugated with the polymers. This review presents the recent developments on polymeric AMP carriers and their potential applications in the biomedical and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

In recent years, the environmental problems accompanying the extensive application of biomedical polymer materials produced from fossil fuels have attracted more and more attentions. As many biomedical polymer products are disposable, their life cycle is relatively short. Most of the used or overdue biomedical polymer products need to be burned after destruction, which increases the emission of carbon dioxide (CO 2 ). Developing biomedical products based on CO 2 fixation derived polymers with reproducible sources, and gradually replacing their unsustainable fossil-based counterparts, will promote the recycling of CO 2 in this field and do good to control the greenhouse effect. Unfortunately, most of the existing polymer materials from renewable raw materials have some property shortages, which make them unable to meet the gradually improved quality and property requirements of biomedical products. In order to overcome these shortages, much time and effort has been dedicated to applying nanotechnology in this field. The present paper reviews recent advances in nanocomposites of CO 2 fixation derived reproducible polymers for biomedical applications, and several promising strategies for further research directions in this field are highlighted., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Liu, Jiang, Xing, Yang, Li and Sun.)

Abstract: Plasma immersion ion implantation and deposition (PIII&D) has been used extensively in microelectronics and metallurgical engineering and its future in biomedical engineering and nanotechnology is even brighter with many novel and burgeoning applications. In this invited review, recent work conducted in the Plasma Laboratory at City University of Hong Kong is described. Advances in direct-current plasma immersion ion implantation, especially non-contact printing and implantation into 3-dimensional components, are discussed. Examples of new applications include fabrication and biological properties of plasma-modified titanium-based materials and control of the surface degradation rate and other properties of biodegradable polymeric and metallic materials. [Copyright &y& Elsevier]

Abstract: Surface engineering using plasma, grafting, and related techniques is an important area in biomaterials research and biomedical engineering. The burgeoning technology enables the modification of selected surface characteristics while the favorable bulk materials properties can be retained. In this invited mini-review, recent work related to surface modification of biomaterials by plasma-based and related techniques conducted in the Plasma Laboratory at City University of Hong Kong is described. Examples of new applications include enhancement of antimicrobial properties and cytocompatibility of plasma and surface-treated and nanostructured biomaterials, corrosion resistance of plasma-treated biodegradable metals, as well as targeted drug delivery capability and magnetic properties of surface-modified silica nanospheres and polymeric micelles. [Copyright &y& Elsevier]

A series of biomedical polyurethane elastomers (PURs) based on poly(ester-carbonate)s (PECs) and polycarbonates (PCs) were synthesized and spectrally characterized fully. PEC or PC diols were synthesized by the ring-opening polymerization of ε-caprolactone, trimethylene carbonate, and neopentyl carbonate catalyzed by lipase from Candida antarctica. PURs were prepared by free-metal method from PEC or PC diols and 4,4′-methylenebis(phenyl isocyanate), with 1,4-butanediol as a chain extender. The physical and mechanical properties as well as hydrolytic stability of the obtained PURs were determined. The toxicity of the received polymers was evaluated using bacterial luminescence test and two protozoans assays. The presented preliminary studies suggest that PEC or PC diols prepared in this way might be applied for the synthesis of biomedical PURs with improved hydrolytic stability. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

Abstract: In biomedical field, a variety of natural or synthetic polymers are being exponentially developed and used in vivo to improve human health. In practical applications, these biopolymers would enter blood circulation directly or indirectly, positively or passively, rapidly or slowly. Blood is a special tissue of human body, which fulfills many important missions to sustain normal metabolism. The contact with blood of the biopolymers, which are seen as foreign substances by the body, would be harmful or even instantaneously lethal, depending on the nature and the dose of the biopolymers administered. Therefore, it is critical to clearly understand the potential influences of the foreign polymers on blood before the polymers are applied from the lab to bedside. In this review, we discuss the recent studies on the interactions of foreign, solubilized polymer molecules (excluding formed polymer materials) with blood constituents (red blood cells, white blood cells, platelets, plasma proteins, etc.), to gain insight into the potential in vivo applications of the biopolymers in the biomedical field. [Copyright &y& Elsevier]

Abstract: The successful development of polymeric drug delivery and biomedical devices requires a comprehensive understanding of the viscoleastic properties of polymers as these have been shown to directly affect clinical efficacy. Dynamic mechanical thermal analysis (DMTA) is an accessible and versatile analytical technique in which an oscillating stress or strain is applied to a sample as a function of oscillatory frequency and temperature. Through cyclic application of a non-destructive stress or strain, a comprehensive understanding of the viscoelastic properties of polymers may be obtained. In this review, we provide a concise overview of the theory of DMTA and the basic instrumental/operating principles. Moreover, the application of DMTA for the characterization of solid pharmaceutical and biomedical systems has been discussed in detail. In particular we have described the potential of DMTA to measure and understand relaxation transitions and miscibility in binary and higher-order systems and describe the more recent applications of the technique for this purpose. [Copyright &y& Elsevier]

The oligoester diols were synthesized via ring-opening polymerization of ε-caprolactone in the presence of creatinine and diethylene glycol or 1,4-butanediol as initiator systems. Thus, obtained oligomers were successfully used in the synthesis of segmented polyurethanes. The oligoester diols (poly(ε-caprolactone) and dihydroxy(polyethylene adipate)) were reacted with 4,4'-methylenebis(phenyl isocyanate) in the presence of 1,4-butanediol as the chain extender to obtain polyurethanes. The physical and mechanical properties of polyurethanes were determined. The structures of the oligoesters and polyurethanes were elucidated by means of NMR, IR and MALDI-TOF MS studies. [ABSTRACT FROM AUTHOR]

Abstract: The controlled release of 5-fluorouracil (5FU) from aliphatic poly(amide urethane)s (PURs) was studied in vitro. Linear PUR conjugates were prepared by the reaction between oligo(ɛ-caprolactone) (PCL), oligolactide (PLA), copolymers of ɛ-caprolactone (CL) and rac-lactide (rac-LA), dihydroxy(polyethylene adipate) (OEDA) with 1,6-diisocyanatohexane (HDI). Release of 5FU from PURs was found to depend on the nature of oligoester units and consist of soft and hard segments. [Copyright &y& Elsevier]

Bioactive polymer/hydroxyapatite (nano)composites are currently being intensively investigated as materials for promotion of bone tissue regeneration and reconstruction. The advantages of polymeric biomaterials, compared to metallic or ceramic materials, are the ease of manufacturing components having various and complex shapes, reasonable cost, and their ability to possess a wide range of physical and mechanical properties. Additionally, hydroxyapatite (HAp) is one of the most attractive materials for bone implants because of its composition and biological similarity to natural tissues. It can be obtained in a nanostructured form, which facilitates its fine dispersion in the polymer matrix as well as producing advantageous interactions with bioactive polymer and tissue. This paper reviews recent advances in polymer/(nano)HAp composites and nanocomposites for bone tissue regeneration, with particular emphasis on the material characteristics. Specific topics associated with polymer/HAp composition, molecular orientation and morphology, surface modifications, the interactions between the components, and their biological behaviours are described. Finally, the challenges facing this emerging field of research are outlined. [ABSTRACT FROM AUTHOR]

Dense CO2 can be used as an environmentally-benign polymer processing medium because of its liquid-like densities and gas-like mass transfer properties. In this work, polymer bio-blends of polycarbonate (PC), a biocompatible polymer, and polycaprolactone (PCL), a biodegradable polymer were prepared. Dense CO2 was used as a reaction medium for the melt-phase PC polymerization in the presence of dense CO2-swollen PCL particles and this method was used to prepare porous PC/PCL blends. To extend the applicability of dense CO2 to the biomedical industry and polymer blend processing, the impregnation of ibuprofen into the blend was conducted and subsequent dissolution characteristics were observed. [ABSTRACT FROM AUTHOR]

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