Aminolysis of poly(hydroxybutyrate)-based multicomponent films for the impregnation of bovine serum albumin

Development of aminolyzed polylactic acid-based porous films for pH-responsive sustained drug delivery devices

Biomaterial-based drug-carrying systems have scored enormous focus in the biomedical sector. Poly(lactic acid) (PLA) is a versatile material in this context. A porous and hydrophilic PLA surface can do this job better. We aimed to synthesize pH-responsive PLA-based porous films for uptaking and releasing amikacin sulfate in the aqueous media. The native PLA lacks functional/polar sites for the said purpose. So, we tended to aminolyze it for tailored physicochemical and surface properties. The amino (-NH2) group density on the treated films was examined using the ninhydrin assay. Electron microscopic analyses indicated the retention of porous morphology after aminolysis. Surface wettability and FTIR results expressed that the resultant films became hydrophilic after aminolysis. The thermal analysis expressed reasonable thermal stability of the aminolyzed films. The prepared films expressed pH-responsive behaviour for loading and releasing amikacin sulfate drug at pH 5.5 and 7.4, respectively. The drug release data best-fitted the first-order kinetic model based on Akaike information and model selection criteria. The prepared PLA-based aminolyzed films qualified as potential candidates for pH-responsive drug delivery applications. This study could be the first report on pH-responsive amikacin sulfate uptake and release on the swellable aminolyzed PLA-based porous films for effective drug delivery application.

PHA is not just a bioplastic!

Polyhydroxyalkanoates (PHA) have evolved into versatile biopolymers, transcending their origins as mere bioplastics. This extensive review delves into the multifaceted landscape of PHA applications, shedding light on the diverse industries that have harnessed their potential. PHA has proven to be an invaluable eco-conscious option for packaging materials, finding use in films foams, paper coatings and even straws. In the textile industry, PHA offers a sustainable alternative, while its application as a carbon source for denitrification in wastewater treatment showcases its versatility in environmental remediation. In addition, PHA has made notable contributions to the medical and consumer sectors, with various roles ranging from 3D printing, tissue engineering implants, and cell growth matrices to drug delivery carriers, and cosmetic products. Through metabolic engineering efforts, PHA can be fine-tuned to align with the specific requirements of each industry, enabling the customization of material properties such as ductility, elasticity, thermal conductivity, and transparency. To unleash PHA's full potential, bridging the gap between research and commercial viability is paramount. Successful PHA production scale-up hinges on establishing direct supply chains to specific application domains, including packaging, food and beverage materials, medical devices, and agriculture. This review underscores that PHA's future rests on ongoing exploration across these industries and more, paving the way for PHA to supplant conventional plastics and foster a circular economy.

Surface treatment of PET multifilament textile for biomedical applications: roughness modification and fibroblast viability assessment

OBJECTIVES

The aim of this study was to investigate the potential of tuning the topography of textile surfaces for biomedical applications towards modified cell-substrate interactions.

METHODS

For that purpose, a supercritical Nitrogen N2 jet was used to spray glass particles on multi-filament polyethylene terephthalate (PET) yarns and on woven fabrics. The influence of the jet projection parameters such as the jet pressure (P) and the standoff distance (SoD) on the roughness was investigated.

RESULTS

The impact of the particles created local filament ruptures on the treated surfaces towards hairiness increase. The results show that the treatment increases the roughness by up to 17 % at P 300 bars and SoD 300 mm while the strength of the material is slightly decreased. The biological study brings out that proliferation can be slightly limited on a more hairy surface, and is increased when the surface is more flat. After 10 days of fibroblast culture, the cells covered the entire surface of the fabrics and had mainly grown unidirectionally, forming cell clusters oriented along the longitudinal axis of the textile yarns. Clusters were generated at yarn crossings.

CONCLUSIONS

This approach revealed that the particle projection technology can help tuning the cell proliferation on a textile surface.

Synthesis of aminolyzed gelatin-mediated chitosan as pH-responsive drug-carrying porous scaffolds

Bio-based drug delivery devices have gained enormous interest in the biomedical field due to their biocompatible attributes. Extensive research is being conducted on chitosan-based devices for drug delivery applications. Chitosan being hydrophobic under neutral conditions makes it difficult to interact with a polar drug of curcumin. We tended to make it polar through sol-gel synthesis and modification via PEGylation, alkaline hydrolysis, and aminolysis. Such alterations could make the chitosan-based scaffolds porous, hydrophilic, amino-functionalized, and pH-responsive. The ninhydrin assay confirmed that a successful aminolysis occurred, and the chemical interaction among the precursors was explained under infrared spectroscopy. The scanning morphology of the optimum aminolyzed membrane appeared to be porous with an average pore size of 320 ± 20 nm. The aminolyzed chitosan membrane was found thermally stable up to 310 °C, hydrophilic with a water contact angle of 23.4°, moderate flowablity, and porous (97 ± 5 %, w/w) against ethanol. The curcumin-loaded chitosan membrane expressed the UV-protection behavior of 99 %. The curcumin-loading and release phenomena were found pH-responsive. The curcumin release results were evaluated through specific kinetic models. This study could be the first report on the amphiphilic, porous, and swellable drug-loaded gelatin/chitosan membrane with pH-responsive loading and release of curcumin for potential drug delivery applications.

Current advances and emerging trends in sustainable polyhydroxyalkanoate modification from organic waste streams for material applications

The current processes for producing polyhydroxyalkanoates (PHAs) are costly, owing to the high cost of cultivation feedstocks, and the need to sterilise the growth medium, which is energy-intensive. PHA has been identified as a promising biomaterial with a wide range of potential applications and its functionalization from waste streams has made significant advances recently, which can help foster the growth of a circular economy and waste reduction. Recent developments and novel approaches in the functionalization of PHAs derived from various waste streams offer opportunities for addressing these issues. This study focuses on the development of sustainable, efficient, and cutting-edge methods, such as advanced bioprocess engineering, novel catalysts, and advances in materials science. Chemical techniques, such as epoxidation, oxidation, and esterification, have been employed for PHA functionalization, while enzymatic and microbial methods have indicated promise. PHB/polylactic acid blends with cellulose fibers showed improved tensile strength by 24.45-32.08 % and decreased water vapor and oxygen transmission rates while PHB/Polycaprolactone blends with a 1:1 ratio demonstrated an elongation at break four to six times higher than pure PHB, without altering tensile strength or elastic modulus. Moreover, PHB films blended with both polyethylene glycol and esterified sodium alginate showed improvements in crystallinity and decreased hydrophobicity.

The Role of Bacterial Polyhydroalkanoate (PHA) in a Sustainable Future: A Review on the Biological Diversity

Environmental challenges related to the mismanagement of plastic waste became even more evident during the COVID-19 pandemic. The need for new solutions regarding the use of plastics came to the forefront again. Polyhydroxyalkanoates (PHA) have demonstrated their ability to replace conventional plastics, especially in packaging. Its biodegradability and biocompatibility makes this material a sustainable solution. The cost of PHA production and some weak physical properties compared to synthetic polymers remain as the main barriers to its implementation in the industry. The scientific community has been trying to solve these disadvantages associated with PHA. This review seeks to frame the role of PHA and bioplastics as substitutes for conventional plastics for a more sustainable future. It is focused on the bacterial production of PHA, highlighting the current limitations of the production process and, consequently, its implementation in the industry, as well as reviewing the alternatives to turn the production of bioplastics into a sustainable and circular economy.