Fabrication and characterization of polyurethane patch loaded with palmarosa and cobalt nitrate for cardiac tissue engineering

Bio-multifunctional noncovalent porphyrin functionalized carbon-based nanocomposite

Herein, in a one-pot method, the reduced graphene oxide layers with the assistance of multiwalled carbon nanotubes were decorated to provide a suitable space for the in situ growth of CoNi₂S₄, and the porphyrins were incorporated into the layers as well to increase the sensitivity of the prepared nanostructure. The prepared nanocomposite can establish π-π interactions between the genetic material and on the surface of porphyrin rings. Also, hydrogen bonds between genetic domains and the porphyrin' nitrogen and the surface hydroxyl groups are probable. Furthermore, the potential donor-acceptor relationship between the d⁷ transition metal, cobalt, and the genetic material provides a suitable way to increase the interaction and gene loading , and transfections. The reason for this phenomenon was optimized to increase the EGFP by up to 17.9%. Furthermore, the sensing ability of the nanocomposite towards H₂O₂ was investigated. In this regard, the limit of detection of the H₂O₂ obtained 10 µM. Also, the in situ biosensing ability in the HEK-293 and PC12 cell lines was evaluated by the addition of PMA. The nanocomposite showed the ability to detect the released H₂O₂ after adding the minimum amount of 120 ng/mL of the PMA.

Recent advances in tissue engineering scaffolds based on polyurethane and modified polyurethane

Organ repair, regeneration, and transplantation are constantly in demand due to various acute, chronic, congenital, and infectious diseases. Apart from traditional remedies, tissue engineering (TE) is among the most effective methods for the repair of damaged tissues via merging the cells, growth factors, and scaffolds. With regards to TE scaffold fabrication technology, polyurethane (PU), a high-performance medical grade synthetic polymer and bioactive material has gained significant attention. PU possesses exclusive biocompatibility, biodegradability, and modifiable chemical, mechanical and thermal properties, owing to its unique structure-properties relationship. During the past few decades, PU TE scaffold bioactive properties have been incorporated or enhanced with biodegradable, electroactive, surface-functionalised, ayurvedic products, ceramics, glass, growth factors, metals, and natural polymers, resulting in the formation of modified polyurethanes (MPUs). This review focuses on the recent advances of PU/MPU scaffolds, especially on the biomedical applications in soft and hard tissue engineering and regenerative medicine. The scientific issues with regards to the PU/MPU scaffolds, such as biodegradation, electroactivity, surface functionalisation, and incorporation of active moieties are also highlighted along with some suggestions for future work.

A New Nanocomposite Copolymer Based On Functionalised Graphene Oxide for Development of Heart Valves

Polymeric heart valves seem to be an attractive alternative to mechanical and biological prostheses as they are more durable, due to the superior properties of novel polymers, and have the biocompatibility and hemodynamics comparable to tissue substitutes. This study reports a comprehensive assessment of a nanocomposite based on the functionalised graphene oxide and poly(carbonate-urea)urethane with the trade name "Hastalex" in comparison with GORE-TEX, a commercial polymer routinely used for cardiovascular medical devices. Experimental data have proved that GORE-TEX has a 2.5-fold (longitudinal direction) and 3.5-fold (transverse direction) lower ultimate tensile strength in comparison with Hastalex (p < 0.05). The contact angles of Hastalex surfaces (85.2 ± 1.1°) significantly (p < 0.05) are lower than those of GORE-TEX (127.1 ± 6.8°). The highest number of viable cells Ea.hy 926 is on the Hastalex surface exceeding 7.5-fold when compared with the GORE-TEX surface (p < 0.001). The platelet deformation index for GORE-TEX is 2-fold higher than that of Hastalex polymer (p < 0.05). Calcium content is greater for GORE-TEX (8.4 mg/g) in comparison with Hastalex (0.55 mg/g). The results of this study have proven that Hastalex meets the main standards required for manufacturing artificial heart valves and has superior mechanical, hemocompatibility and calcific resistance properties in comparison with GORE-TEX.