Preparation, characterization and hydrolytic degradation of PLA/PCL co-mingled nanofibrous mats prepared via dual-jet electrospinning

One Year Evaluation of Material Properties Changes of Polylactide Parts in Various Hydrolytic Degradation Conditions

Biodegradable biocompatible materials are widely used in medical applications. Determining the possibility of using biodegradable materials depends on determining the changes in their parameters over time due to degradation. The current scientific research on biodegradable materials has presented results based on research methods characterized by the different geometry and cross-section size of the specimen, type of degradation medium, or different pH value of the medium or maximum degradation time. This paper presents the results of a one-year study on the influence of the type of degradation medium on the changes in mechanical behavior and the uptake of the degradation medium by biodegradable specimens with large cross-sections. In addition, a prototype of a test stand was created, which allowed for the specimens to be stored vertically to ensure regular medium exposure and eliminate the interaction of the surface of the tested specimens with the sides of the container. The obtained results allowed the statistical significance of differences in the mechanical parameters determined in the uniaxial tensile test after 2, 4, 6, 12, 26, 39, and 52 weeks of degradation to be indicated depending on the type of degradation medium. It was proven that the changes in mechanical behavior depend on the percentage change in the mass of the specimens during degradation. The percentage change in mass depends on the type of degradation medium. Based on the results of this research, it was noted that in long-term degradation above 12 weeks, buffered sodium chloride solution is the optimal choice for the degradation medium. However, distilled water or physiological saline solution can be used as an alternative during the degradation period for up to 12 weeks.

Long-term in vitro degradation behavior and biocompatibility of polycaprolactone/cobalt-substituted hydroxyapatite composite for bone tissue engineering

OBJECTIVE

Currently, infections due to foreign-body reactions caused by bacteria or implant materials at the wound site are one of the major reasons for the failure of guided tissue regeneration (GTR) and guided bone regeneration (GBR) in clinical applications. The purpose of this study was to develop regeneration membranes with localized cobalt ion release to reduce infection and inflammation by polycaprolactone (PCL)/cobalt-substituted hydroxyapatite (CoHA).

METHODS

The PCL composite membrane containing 20 wt% CoHA powders was prepared by solvent casting. The surface morphology, crystal structure, chemical composition and thermal properties of PCL composite membranes were characterized. The biocompatibility, osteogenic differentiation and antibacterial properties of composite membrane were also investigated. Then, in biodegradability was assessed by immersing phosphate buffer solution (PBS) for 6 months.

RESULTS

Physicochemical analyses revealed that CoHA is evenly mixed in the membranes and assistance reduce the crystallinity of PCL for getting more degradation amounts than PCL membrane. Osteoblast cells culture on the membrane showed that the CoHA significantly increases cell proliferation and found the calcium deposition production increased over 90% compared with PCL after 7 days of culture. A good antibacterial effect was achieved by the addition of CoHA powder. The results were confirmed by 2.4 times reduction of proliferation of Escherichia coli (E. coli) seeded on the composite membrane after 24 h. Immersing in PBS for 6 months indicated that PCL-CoHA composite membrane has improved biodegradation and can continuously remove free radicals to reduce the inflammatory response.

SIGNIFICANCE

The PCL-CoHA composite membrane with suitable releasing of cobalt ion can be considered as a potential choice for bone tissue regeneration.

Antimicrobial additives for poly(lactic acid) materials and their applications: current state and perspectives

Poly(lactic acid)-based antimicrobial materials received considerable attention as promising systems to control microbial growth. The remarkable physicochemical properties of PLA such as renewability, biodegradability, and US Food and Drug Administration (FDA) approval for clinical use open up interesting perspectives for application in food packaging and biomedical materials. Nowadays, there is an increasing consumer demands for fresh, high-quality, and natural foods packaged with environmentally friendly materials that prolong the shelf life. The incorporation of antimicrobial agents into PLA-based polymers is likely to lead to the next generation of packaging materials. The development of antimicrobial PLA materials as a delivery system or coating for biomedical devices is also advantageous in order to reduce possible dose-dependent side effects and limit the phenomena of antibiotic resistance. This mini-review summarizes the most recent advances made in antimicrobial PLA-based polymers including their preparation, biocidal action, and applications. It also highlights the potential of PLA systems as efficient stabilizers-carriers of various kinds of antimicrobial additives including essential oils and other natural compounds, active particles and nanoparticles, and conventional and synthetic molecules.