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This study examines the high-strain rate behavior of shear thickening fluid (STF)-encapsulated samples of an electrospun mat. It comprises sandwich layers of STF-impregnated ultra-high molecular weight polyethylene (UHMWPE)/high-density polyethylene (HDPE) mat enclosed within high-temperature stretched electrospun neat UHMWPE fabric. The UHMWPE/HDPE mat was chosen for STF impregnation due to its porosity and the texture of its fiber surface, which contains pores, pits, wrinkles, and grooves ranging in size from nano- to micron-scale. This feature enhances the adhesion and absorption of STF into the fiber structure and onto the fiber surface. These STF-contained and corresponding neat samples were tested using an in-house-designed split-Hopkinson pressure bar. The deformation and fracture behavior of samples were also monitored simultaneously using a highspeed camera. The results showed that at a higher strain rate, the peak stress and energy absorption of STF-encapsulated samples were more elevated due to increased inter-fiber friction, unlike neat samples, which show a declining trend in peak stress and energy absorption due to yam slippage. Moreover, the deformation during impact in neat samples was higher than in the STF-encapsulated samples. Highlights * Electrospun ultra-high molecular weight polyethylene and its HDPE blended fibers * Interconnected pores and pits facilitated shear thickening fluid (STF) impregnation. * STF-encapsulation improved peak stress and toughness at high-strain rates. KEYWORDS electrospinning, HDPE, shear thickening fluid, split-Hopkinson pressure bar, UHMWPE, 1 | INTRODUCTION The recent development of composite strengthening materials using nanotechnology is gathering much attention, from medical to defense applications. Soft body armor typically consists of fabrics or laminates [...]

Poly(lactic acid) (PLA) is one of the most promising biopolymers extensively used in food, packaging, medical and pharmaceutical industries. It is due to favorable physicochemical properties, in-situ hydrolytic degradation and well-established processing parameters. However, in medical engineering applications, PLA shows some drawbacks like low cell adhesion, biological inertness, slow degradation rate and high acid inflammation. These shortcomings of pure PLA could be addressed by blending it with other bioresorbable materials and compatibilizers. This review provides comprehensive information on different PLA composites in the field of tissue engineering, implants, injury management and drug delivery systems. The PLA-based composites are divided into four parts: PLA/polymer, PLA/metal, PLA/ceramic, and PLA/nanoparticles. It also investigates various synthesis process, role of different compatibilizers, in vitro studies and their in vivo applications. Highlights * Review the trends of bioresorbable PLA blends/composites. * Extensively focused on PLA blend with polymer, metal, ceramic, and nanoparticles. * Role of reinforcement and compatibilizer to overcome shortcomings of PLA implant. * Highlights advantages, limitations, and properties of different types of PLA implants. * Discuss various clinical applications and future of PLA blends/composite scaffolds. KEYWORDS biomaterial, compatibilizer, PLA composite, PLA implants, PLA nanoparticles, 1 | INTRODUCTION A wide range of bioresorbable polymeric materials (BPM) has been investigated for biomedical engineering applications. The major advantage of BPM is to eliminate the need for a [...]

Bioresorbable polymeric stents (BPS) can become a promising alternative over permanent stents, as it reduce in-stent thrombosis, endothelial dysfunction, and thrombogenicity. Although, a few limitations like uncontrolled degradation, inadequate strength, and lack of radiopacity restrict its application. Thus, a novel bioresorbable radiopaque Mg-Zn-Y Alloy (BRM) of high effective atomic number ([Z.sub.eff]) was developed to reinforce and attenuate X-rays in the polymers. After that, the optimized BRM microparticles were blended with radiolucent poly (L-lactide)/poly ([epsilon]-caprolactone) (PLLA/PCL) polymer and extruded into biaxially expanded (BAE) tubes. Further, in this work, BAE tubes of PLLA/PCL/ BRM and PLLA/PCL were cut using the optimized Femtosecond laser machine (FSLM) parameters for fabricating cardiovascular stents. These stent materials were assessed to sustain the angioplasty procedure, such as radial strength, crimping, recoil, expansion process, and performance under cycling loading. Highlights * A novel biodegradable radiopaque Mg-Zn-Y alloy was developed. * Adding Mg alloy (5% wt.) in PLLA/PCL imparts X-ray visibility. * Composite stents show better compressive radial strength and flexibility. * It also reveals low crimping recoil, expansion recoil, and foreshortening. * Composite stents can withstand arterial vasomotion better than PLLA/PCL. KEYWORDS Biopolymer, Bioresorbable polymer, Composite stents, Crimping, Radiopacity, Recoil, 1 | INTRODUCTION Today, metallic stents are preferred due to their high impact strength, wear resistance, ductility, and toughness. (1) It demonstrates a high success rate in Percutaneous Coronary Intervention [...]

A state of hypoxia (lack of oxygen) persists in the initial and later phases of healing in cardiovascular diseases, which can alter the tissue's repair or regeneration, ultimately affecting the structure and functionality of the related organ. Consequently, this results in a cascade of events, leading to metabolic stress and the production of reactive oxygen species (ROS) and autophagy. This unwanted situation not only limits the oxygen supply to the needy tissues but also creates an inflammatory state, limiting the exchange of nutrients and other supplements. Consequently, biomaterials have gained considerable attention to alleviate hypoxia and oxidative stress in cardiovascular diseases. Numerous oxygen releasing and antioxidant biomaterials have been developed and proven to alleviate hypoxia and oxidative stress. This review article summarizes the mechanisms involved in cardiovascular pathologies due to hypoxia and oxidative stress, as well as the treatment modalities currently in practice. The applications, benefits and possible shortcomings of these approaches have been discussed. Additionally, the review explores the role of novel biomaterials in combating the limitations of existing approaches, primarily focusing on the development of oxygen-releasing and antioxidant biomaterials for cardiac repair and regeneration. It also directs attention to various other potential applications with critical insights for further advancement in this area. [ABSTRACT FROM AUTHOR]

Tracheoesophageal voice prostheses (TEPs) are soft polymeric devices used to restore the voices of patients who have undergone total laryngectomy (TL). TEPs are implanted on the tracheoesophageal wall and come in direct contact with food, fluid and air. The environment of an implant is a budding ground for growth of microbes, leading to biofilm formation on the TEP surfaces. Biofilm formation is the leading cause of TEP failure because the biofilm affects its functioning by clogging the air passage over several weeks to a few months. Short useful lifespan of TEPs is a concern for patients undergoing total laryngectomy. To increase the useful lifespan of TEPs, it is imperative to prevent biofilm formation. This problem is addressed in the present study by developing a cationic crosslinked antimicrobial coating that prevents biofilm formation through contact killing. An acrylate-based tetracopolymer poly(methyl methacrylate [MMA]-co-nbutyl acrylate [BA]-co-dimethylaminoethyl methacrylate [DMAEMA]-co-2 hydroxyethyl methacrylate [HEMA]) was synthesized by free radical polymerization and was crosslinked by hexamethylene diisocyanate (THDI) trimer through urethane linkages. The crosslinked tetracopolymer coatings were subjected to quaternary ammonium formation through N-alkylation with iodooctane. Different variants of coatings were synthesized and the tetracopolymer with 22.5% MMA, 22.5% BA, 20% HEMA and 35% DMAEMA showed desirable results. The developed coatings were characterized and tested for safety as well as mechanical and antimicrobial efficacy. The final results showed that the developed coatings exhibited good cytocompatibility, haemocompatibility, mechanical properties and antimicrobial properties for 180 days against E. coli, S. aureus and C. albicans. [ABSTRACT FROM AUTHOR]

All bioresorbable polymeric implants are radiolucent, making them undetectable under the X-rays. Therefore, to improve their X-ray visibility, the high effective atomic number (Zeff) material such as Pt, Au, Ta, Ba, or its alloy are attached to the body of the bioresorbable implant. However, during the in vivo degradation, these bio-inert heavy metals can either detach or leach out from the lesion site and accumulate into the vital organ, leading to severe health complications. Thus, as a strategy, the novel biodegradable and radiopaque Mg alloy was produced to impart X-ray visibility in the biopolymer. Here, the Mg was alloyed with the optimized ratio of heavy metals, i.e., Zn and Y. The radiopaque Mg alloy was characterized and powdered to the size of 25–20 µm. Further, it was blended with radiolucent Poly-L-lactic acid (PLLA) and polycaprolactone (PCL) polymer. The Bi-axially expanded (BAE) tubes of PLLA/PCL and PLLA/PCL/Mg alloy (5% wt.) were extruded for fabricating cardiovascular stents. The BAE tube comparison studies were performed for thermal stability, wettability, surface roughness, and mechanical properties. The potential of 5% Mg alloy in the polymeric matrix was evaluated as a nucleating, reinforcing, and radiopaque agent. In vitro accelerated degradation study was performed in the physiological fluid to evaluate the pH variation and decomposition rate. Finally, in vitro biocompatibility was assessed by evaluating the behavior of L929 fibroblast cells, followed by the blood biocompatibility test on the blends. [ABSTRACT FROM AUTHOR]