# Editorial on Special Issue \"Biomaterials, Polymers and Tissue Engineering\"
###### Abstract
The authors developed a new formulation of oil-in-water-type microemulsions to enhance the bioavailability of spinonolactone (SP), a mineralocorticoid used to prevent ischemia- and reperfusion-induced renal injuries. The results showed that the kidney oxidative injury was only partially restored after SP administration, but nano-encapsulated SP has beneficial effects in preventing kidney damage and renal oxidative stress in a rat model. The field of induced pluripotent stem cells (iPSCs) has gained importance in recent years, contributing to the development of therapeutic research and regenerative medicine. Their potential to differentiate into various tissues or cells attracted the interest of researchers. For instance, [PERSON] et al. developed an alternative method for reprogramming, using small molecules and external stimuli, without the use of transgenes [7]. The authors showed that vitamin C improved iPSC generation from mouse and human somatic cells with transgenes. Current economic and environmental issues drew the attention of researchers and motivated them to develop new strategies to valorize the biomass into valuable products. An example is the work of [PERSON] et al., published in this Special Issue. The authors used chicken feathers as source of keratin through microbial degradation. The keratin peptides were fractionated, according to their molecular weight, and their effect on keratinocyte migration and metabolic activity as well as on macrophage release of TNF-\(\alpha\) was evaluated [8]. The resulting peptides induced significant changes in the viability and migration rate of keratinocytes, depending on the size distribution (fraction). Thus, the cell's response can be modulated to either increase or decrease in their migration rate and metabolic activity. Additive manufacturing has attracted tremendous attention due to its high versatility and functionality. Different 3D-printing techniques hold an important place in numerous biological and biomedical applications. Specifically, stereolithography (SLA) is an emerging technology for the fabrication of complex structures, such as scaffolds for tissue engineering, microfluidic devices, implantable drug-delivery systems, and items for dental reconstruction [9; 10; 11; 12]. With the advancement of the SLA technique, the fabrication of 3D-printedcomposites with enhanced functionality and efficacity, with improved performance and widened applications, can be achieved. In this context, continuous innovation is needed to produce new materials suitable for SLA, which are easily processable, cost-effective, and characterized by good stability during storage. New discoveries surrounding the composition of the resins used in 3D printing include the addition of nanofillers, which make them feasible for manufacturing composites with superior mechanical strength. Graphene is a nanofiller of choice and several studies developing successful graphene/photopolymer resins for the SLA technique have been reviewed [13]. Another 3D-printing process is fused deposition modelling (FDM), which is widely used in the automobile industry, aerospace industry, and in the medical sector, due to its simplicity and cost-effectiveness. Polylactic acid (PLA) is one of the most popular materials for 3D printing with FDM, due to its ease of use. PLA is a thermoplastic, semi-crystalline polyester, with good strength and stiffness; however, it possesses brittleness and slow crystallization. [PERSON] and [PERSON] have shown that a styrene-ethylene-butylene-styrene (SEBS) thermoplastic elastomer acts as a nucleating agent in blends with PLA, and increases the initial temperature of crystallization [14]. Moreover, the impact strength increased with the addition of SEBS (up to 3%); meanwhile, in the bending tests, the specimens containing more than 3% were no longer broken.