Nearly 20 years have passed since Weinberg and Bell attempted to make the first tissue-engineered blood vessels. Following this early attempt, vascular tissue engineering has emerged as one of the most promising approaches to fabricate orderly and mechanically competent vascular substitutes. In elastic and muscular arteries, elastin is a critical structural and regulatory matrix protein and plays an important and dominant role by conferring elasticity to the vessel wall. Elastin also regulates vascular smooth muscle cells activity and phenotype. Despite the great promise that tissue-engineered blood vessels have to offer, little research in the last two decades has addressed the importance of elastin incorporation into these vessels. Although cardiovascular tissue engineering has been reviewed in the past, very little attention has been given to elastin. Thus, this review focuses on the recent advances made towards elastogenesis and the challenges we face in the quest for appropriate functional vascular substitutes.

Bioadhesives reduce operation time and surgical complications. However, in the presence of blood, adhesion strength is often compromised. Inspired by the blood clotting activity of snake venom, we report a visible light–induced blood-resistant hemostatic adhesive (HAD) containing gelatin methacryloyl and reptilase, which is a hemocoagulase (HC) extracted from Bothrops atrox. HAD leads to the activation and aggregation of platelets and efficiently transforms fibrinogen into fibrin to achieve rapid hemostasis and seal the tissue. Blood clotting time with HAD was about 45 s compared with 5 to 6 min without HAD. HAD instantaneously achieved hemostasis on liver incision (~45 s) and cut rat tail (~34 s) and reduced blood loss by 79 and 78%, respectively. HAD is also efficient in sealing severely injured liver and abdominal aorta. HAD has great potential to bridge injured tissues by combing hemostasis with adhesives.

Advanced polymeric controlled delivery systems are designed to effectively treat chronic diseases by adjusting the temporal profile of drug release. Most conventional controlled‐release carriers provide a constant and sustained‐release profile of therapeutics for an extended time. Although these systems have improved the patients’ compliance and adherence and have reduced the administration frequency, they cannot be used for optimal treatment of diseases that require variable patterns of drug release in the treatment regimen. These patterns and the specific rhythms of medical conditions determined by both the body's internal biological clock cycles (i.e., circadian rhythm) and each patient's characteristics call for patient‐specific controlled drug‐delivery systems that can provide adjustable drug release profiles. The importance of individualized therapy and the variety of biodegradable polymers with tunable physicochemical properties promote the design and manufacturing of polymeric delivery systems that release therapeutics at controllable rates. In the past two decades, novel biomaterials and fabrication methods have been utilized to improve the traditional drug‐delivery design and manufacturing technologies. This review article provides a critical discussion of emerging polymeric controlled‐release systems and the mechanisms through which they release their therapeutic agents. Advances and challenges in the design and the fabrication processes of polymeric drug‐delivery systems, particularly solid oral dosage forms and implantable microchips, with controllable release profiles of drugs, are reviewed, focusing on the application of microtechnology and 3D printing techniques in their manufacturing.

Strategies for bone tissue engineering and regeneration rely on bioactive scaffolds to mimic the natural extracellular matrix and act as templates onto which cells attach, multiply, migrate and function. Of particular interest are nanocomposites and organic-inorganic (O/I) hybrid biomaterials based on selective combinations of biodegradable polymers and bioactive inorganic materials. In this paper, we review the current state of bioactive and biodegradable nanocomposite and O/I hybrid biomaterials and their applications in bone regeneration. We focus specifically on nanocomposites based on nano-sized hydroxyapatite (HA) and bioactive glass (BG) fillers in combination with biodegradable polyesters and their hybrid counterparts. Topics include 3D scaffold design, materials that are widely used in bone regeneration, and recent trends in next generation biomaterials. We conclude with a perspective on the future application of nanocomposites and O/I hybrid biomaterials for regeneration of bone.