Macromolecular bioscience最新文献

Chronic wounds present significant clinical challenges due to the high risk of infections and persistent inflammation. While personalized treatments in point-of-care settings are crucial, they are limited by the complex fabrication techniques of the existing products. The calcium sulfate hemihydrate (CSH)-based drug delivery platform enables rapid fabrication but lacks antioxidant and antibacterial properties, essential to promote healing. To develop a multifunctional platform, a tannic acid (TA)-silk fibroin (SF) complex is engineered and incorporated as an additive in CSH cement. This cement is then cast into pellets to create silk/bioceramic-based composite drug delivery systems, designed for point-of-care use. Compared to neat CSH pellets, the composite pellets exhibit a 7.5-fold increase in antioxidant activity and prolonged antibacterial efficacy (up to 13 d). Moreover, the subcutaneous implantation of the pellets shows no hallmarks of local or systemic toxicity in a rodent model. The pellets are optimized in composition and fabrication to ease market translation. Clinically, the pellets have the potential to be further developed into products to place on wound beds or fill into bone cavities that are designed to deliver the intended therapeutic effect. The developed multifunctional system proves to be a promising solution for personalized treatment in point-of-care settings.

Collagen (Col) is commonly used as a natural biomaterial for biomedical applications. Although Col I is the most prevalent col type employed, many collagen types work together in vivo to confer function and biological activity. Thus, blending collagen types can better recapitulate many native environments. This work investigates how hydrogel properties can be tuned through blending collagen types (col I/II and col I/III) and by varying polymerization temperatures. Col I/II results in poorly developed fibril networks, which softened the gels, especially at lower polymerization temperatures. Conversely, col I/III hydrogels exhibit well-connected fibril networks with localized areas of fine fibrils and result in stiffer hydrogels. A decreased molecular mass recovery rate is observed in blended hydrogels. The altered fibril morphologies, mechanical properties, and biological signals of the blended gels can be leveraged to alter cell responses and can be used as models for different tissue types (e.g., healthy vs fibrotic tissue). Furthermore, the biomimetic hydrogel properties are a tool that can be used to modulate the transport of drugs, nutrients, and wastes in tissue engineering applications.

Significant progress has been made in tissue engineering (TE), aiming at providing personalized solutions and overcoming the current limitations of traditional tissue and organ transplantation. 3D bioprinting has emerged as a transformative technology in the field, able to mimic key properties of the natural architecture of the native tissues. However, most successes in the area are still limited to avascular or thin tissues due to the difficulties in controlling the vascularization of the engineered tissues. To address this issue, several molecules, biomaterials, and cells with pro- and anti-angiogenic potential have been intensively investigated. Furthermore, different bioreactors capable to provide a dynamic environment for in vitro vascularization control have been also explored. The present review summarizes the main molecules and TE strategies used to promote and inhibit vascularization in TE, as well as the techniques used to deliver them. Additionally, it also discusses the current challenges in 3D bioprinting and in tissue maturation to control in vitro/in vivo vascularization. Currently, this field of investigation is of utmost importance and may open doors for the design and development of more precise and controlled vascularization strategies in TE.

The study investigates the potentials of the rapid crosslinking hydrogel concoction comprising of natural silk fibroin (SF) and recombinant tailorable collagen-like protein with binding domains for wound repair. The formation of dityrosine crosslinks between the tyrosine moieties augments the formation of stable hydrogels, in the presence of the cytocompatible photo-initiator riboflavin and visible light. This uniquely engineered PASCH (Photo-activated silk fibroin and tailor-made collagen-like protein hydrogel) confers the key advantage of improved biological properties over the control hydrogels comprising only of SF. The physico-chemical characterization of the hydrogels with respect to crosslinking, modulus, and thermal stability delineates the ascendancy of PASCH 7:3 over other combinations. Furthermore, the hybrid protein hydrogel proves to be a favorable cellular matrix as it enhances cell adhesion, elongation, growth, and proliferation in vitro. Time-lapse microscopy studies reveal an enhanced wound closure in human endothelial cell monolayer (EA.hy926), while the gene expression studies portray the dynamic interplay of cytokines and growth factors in the wound milieu facilitating the repair and regeneration of cells, sculpted by the proteins. The results demonstrate the improved physical and biological properties of fabricated PASCH, depicting their synergism, and implying their competency for use in tissue engineering applications.

Chagas disease, caused by Trypanosoma cruzi (T. cruzi), affects millions worldwide, particularly in Latin America. Despite its prevalence, treatment options remain limited. Current drugs, such as benznidazole, cause adverse effects possibly due to ineffective administration. In this context, nanoparticles offer a promising solution to target and control drug delivery by leading the effector site and minimizing side effects. This article focuses on zein-casein-based nanoparticles (Bioparticles, BP) coated with Eudragit L100-55 (BP:EU) for enteric delivery of benznidazole. BP:EU structures are synthesized to minimize premature drug release in the stomach, promoting release in the small intestine. Physical characterization confirmed the successful synthesis of BP:EU and their pH-responsive trigger for drug release. These findings suggest that this material can be a promising approach for Chagas disease treatment, addressing challenges in benznidazole delivery that can lead to improved therapeutic responses.

While significant progress has been made in creating polymeric structures for tissue engineering, the therapeutic application of these scaffolds remains challenging owing to the intricate nature of replicating the conditions of native organs and tissues. The use of human-derived biomaterials for therapeutic purposes closely imitates the properties of natural tissue, thereby assisting in tissue regeneration. Decellularized extracellular matrix (dECM) scaffolds derived from natural tissues have become popular because of their unique biomimetic properties. These dECM scaffolds can enhance the body's ability to heal itself or be used to generate new tissues for restoration, expanding beyond traditional tissue transfers and transplants. Enhanced knowledge of how ECM scaffold materials affect the microenvironment at the injury site is expected to improve clinical outcomes. In this review, recent advancements in dECM scaffolds are explored and relevant perspectives are offered, highlighting the development and application of these scaffolds in tissue engineering for various organs, such as the skin, nerve, bone, heart, liver, lung, and kidney.

Back Cover: In article 2400084, Filippo Rossi and co-workers develop a magnetic bijel-like structure to load and release different types of molecules (hydrophilic and hydrophobic). The use of ε-caprolactone is explored, which can polymerize, forming hydrophobic domains (oil phase). After mixing with iron oxide nanoparticles (NPs), the water dispersion creates a magnetic biphasic porous structure without phase separation.

Mineralization of scaffolds is essential for alveolar ridge preservation and bone tissue engineering, enhancing the mechanical strength and bioactivity of scaffolds, and promoting better integration with natural bone tissue. While the in situ mineralization method using concentrated SBF solutions is promising, there is limited comprehensive research on its effects. In this study, it is demonstrate that soaking gelatin/alginate scaffolds (GAS) in fivefold concentrated SBF significantly reduces the mineralization time to 3–7 days but also leads to considerable degradation and loss of the scaffold's original microstructure. The ratio of gelatin to alginate is optimized to improve the properties of GAS. The optimized GAS sample, when soaked in concentrated SBF to form GAS/HAp, exhibited hydroxyapatite (HAp) crystal formation starting from day 3, with mature hexagonal crystals forming by day 7. However, this process also caused significant decomposition and deformation of the scaffold's pore structure. Additionally, the biocompatibility of GAS and GAS/HAp is evaluated through in vitro, in ovo, haemolysis, and anti-ROS assays. The findings highlight the impact of SBF_5× on the mineralization of GAS, laying the groundwork for further research in alveolar ridge preservation and bone tissue engineering.

Front Cover: In article 2400080, Hui Cheng and co-workers introduce a temperature-sensitive hydrogel with photothermal conversion capabilities. The cover shows how the hydrogel works. The temperature-sensitive hydrogel is injected to fill the entire wound, and then excited by near-infrared light, the hydrogel exerts a photothermal effect, raising the temperature to kill bacteria and ultimately promoting tissue healing.