Additive manufacturing (AM), also referred to as three-dimensional printing/printed (3DP), has emerged as a transformative approach in the current design and manufacturing of various biomaterials for the restoration of damaged tissues inside the body. This advancement has greatly aided the development of customized biomedical devices including implants, prosthetics, and orthotics that are specific to the patients. In tissue engineering (TE), AM enables the fabrication of complex structures that promote desirable cellular responses in the regeneration of tissues. Since the choice of biomaterials plays a vital role in scaffold performance as well as cellular responses, meticulous material selection is essential in optimizing the functionality of scaffolds. These scaffolds often possess certain characteristics such as biodegradability, biocompatibility, biomimicry, and porous structure. To this end, polymers such as chitosan, collagen, alginate, hyaluronic acid, polyglycolic acid, polylactic acid, and polycaprolactone have been extensively investigated in the fabrication of tissue-engineered scaffolds. Furthermore, combinations of biomaterials are also utilized to further enhance the scaffolds’ performance and functionality. This review discusses the principle of AM and explores recent advancements in AM technologies in the development of TE and regenerative medicine. In addition, the applications of 3DP, polymer-based scaffolds will be highlighted.

Objective: Bigels are unique semi-solid preparations that have piqued the focus of numerous scientists owing to their significant advantages over ordinary gels. The purpose of this study was to develop and characterize innovative Bigels for applications in drug delivery by combining Hydroxypropyl methylcellulose hydrogel and sorbitan monostearate, oils like coconut and olive-based organogel. The existence of both aqueous and oil phases as bigel was revealed by microscopy. Methods: Hydrogels and organogels were prepared separately, and bigels were formed by combining hydrogel and organogel in a predetermined ratio. They were then analyzed employing various physicochemical tests i. e in vitro drug release, microscopy, and other techniques. Microscopy, viscosity measurement, mechanical analysis, and differential scanning calorimetry were used to examine the bigel's microstructures and physicochemical properties. Results: Tube inversion tests reveal that the bigel doesn’t flow under its own weight till 167 min. The microscopy suggested that the gels exhibited fiber-like structures due to the trapping of the organogel inside hydrogel molecules; this entrapment was demonstrated to be uniformly accomplished, resulting in formulation stability, and the DSC study reveals that the terbinafine is not decomposed also after formulating in bigel, and the terbinafine bigel was also found to be stable. The drug-loaded gels demonstrated effective antibacterial activity against Candida species. The formulated bigel shows initial release in 2 h and slowly release later in 4 h. The formed bigel is found to be stable after 3 mo with a pH range of 7.07±0.04, showing good spreadability and drug content was 99.99±0.75. Conclusion: Terbinafine, the drug of preference for the treatment of bacterial vaginosis, demonstrated diffusion-mediated drug release when placed into bigels. In general, the produced bigels might be employed as delivery vehicles for drugs delivered vaginally.

Poor vascularization is one of the basic obstacles to the regeneration of functioning tissues because an oxygen diffusion process and elimination of wastes are essential in preserving the grafts. Recently, biomaterials have allowed the invention of bioinspired polymer scaffolds and replicated the natural extracellular matrix (ECM) due to the mechanical tunability of the synthetic polymers with the biological signals of natural macromolecules. The review uses a mechanistic analysis of the strategies to improve angiogenesis by using surface topography modification, bioactive peptide incorporation and pre-vascularization. Another way to achieve complex, perfusable topologies is by using more sophisticated methods of fabrication, such as electrospinning, 3D/4D bioprinting, or microfluidics. Based on in vitro and in vivo results, we determine angiogenic effectiveness by using cellular assays and animal transfers, pointing towards the translational advances in patents and clinical uses of bone, cardiac, nervous, and skin tissues. In spite of the substantial improvements, large-scale production and high demands of the regulations still exist. The future directions include the incorporation of bioinspired designs and intelligent materials, nanotechnology, and AI-based optimization into developing patient-specific and adaptive scaffolds. The following innovations herald the advent of highly effective constructs that can be used to regenerate tissue and overcome the limitations of present tissue engineering therapies through the introduction of highly effective, vascularized constructs.

Objective: Metformin hydrochloride is a biguanide derivative that is commonly used to treat type 2 diabetes. Metformin has a low oral bioavailability of 50% to 60 %. To overcome these challenges, metformin was used as a Pgp substrate in this research work and used in conjunction with natural P-gp inhibitors. Methods: The study commenced with a chicken non-everted gut sac model that closely resembled in vivo intestinal transport processes. The effect of different P-gp inhibitors on Metformin intestinal permeability was examined in this study to fully recognize the potential significance of Pgp and intestinal metabolism. Results: After evaluating the effectiveness of different P-gp inhibitors at different concentration concentrations i.e. Piperine, Ginger, Drumstick, and Verapamil (standard) at (2 mg/ml, 4 mg/ml, and 6 mg/ml) by non-everted gut sac study. At 2 mg/ml ginger and drumstick could not show any significant improvement. At 4 mg/ml also drumstick could not show any significant improvement in percentage drug permeation. At 6 mg/ml all three natural inhibitors show a significant difference in percentage drug permeation when compared using the f2 similarity index. But piperine was found to be the most potent of all 3 inhibitors because it shows complete release with higher permeation in less time than ginger and drumstick when given in conjunction with Metformin. Then the comparative permeation study of different concentrations (i.e. 2 mg/ml, 4 mg/ml, and 6 mg/ml) of P-gp inhibitors was carried out using the f2 similarity parameter and was that there is no significant difference in the percentage of drug permeation of Metformin in the presence of 2 mg/ml versus 4 mg/ml inhibitors. The same is with 4 mg/ml versus 6 mg/ml of inhibitors. However, when the percentage drug permeation of Metformin in the presence of 2 mg/ml as compared to 6 mg/ml, a significant difference was observed. Conclusion: It was concluded from this research work that Piperine shows significant improvement in % drug permeation when compared using the f2 similarity index and its formulation with metformin may offer a simple and safe approach to enhance the pharmacological profile of metformin for effective anti-diabetic therapy in humans.