Scaffold biomaterials and nano-based therapeutic strategies for skeletal muscle regeneration

Skeletal muscle is integral to the functioning of the human body. Several pathological conditions, such as trauma (primary lesion) or genetic diseases such as Duchenne muscular dystrophy (DMD), can affect and impair its functions or exceed its regeneration capacity. Tissue engineering (TE) based on natural, synthetic and hybrid biomaterials provides a robust platform for developing scaffolds that promote skeletal muscle regeneration, strength recovery, vascularization and innervation. Recent 3D-cell printing technology and the use of nanocarriers for the release of drugs, peptides and antisense oligonucleotides support unique therapeutic alternatives. Here, the authors present recent advances in scaffold biomaterials and nano-based therapeutic strategies for skeletal muscle regeneration and perspectives for future endeavors.

Biomaterials and Meniscal Lesions: Current Concepts and Future Perspective

Menisci are crucial structures for knee homeostasis. After a meniscal lesion, the golden rule, now, is to save as much meniscus as possible; only the meniscus tissue that is identified as unrepairable should be excised, and meniscal sutures find more and more indications. Several different methods have been proposed to improve meniscal healing. They include very basic techniques, such as needling, abrasion, trephination and gluing, or more complex methods, such as synovial flaps, meniscal wrapping or the application of fibrin clots. Basic research of meniscal substitutes has also become very active in the last decades. The aim of this literature review is to analyze possible therapeutic and surgical options that go beyond traditional meniscal surgery: from scaffolds, which are made of different kind of polymers, such as natural, synthetic or hydrogel components, to new technologies, such as 3-D printing construct or hybrid biomaterials made of scaffolds and specific cells. These recent advances show that there is great interest in the development of new materials for meniscal reconstruction and that, with the development of new biomaterials, there will be the possibility of better management of meniscal injuries

Antibacterial Activity and Iron Release of Organic-Inorganic Hybrid Biomaterials Synthesized via the Sol-Gel Route

The aim of this work was the synthesis of hybrid materials of iron (II)-based therapeutic systems via the sol-gel method. Increasing amounts of polyethylene glycol (PEG 6, 12, 24, 50 wt%) were added to SiO2/Fe20 wt% to modulate the release kinetics of the drug from the systems. Fourier-transform infrared (FTIR) spectroscopy was used to study the interactions between different components in the hybrid materials. The release kinetics in a simulated body fluid (SBF) were investigated, and the amount of Fe2+ released was detected via ultraviolet-visible spectroscopy (UV-Vis) after reaction with ortho-phenanthroline. Furthermore, biological characterization was carried out. The bioactivity of the synthesized hybrid materials was evaluated via the formation of a layer of hydroxyapatite on the surface of samples soaked in SBF using spectroscopy. Finally, the potential antibacterial properties of seven different materials against two different bacteria—E. coli and S. aureus—were investigated.

In Vivo Behavior of Bioactive Glass-Based Hybrids in Animal Models For Bone Regeneration

This review presents the recent advances and the current state-of-the-art of bioactive glass-based hybrid biomaterials for bone regeneration. Hybrid materials comprise two (or more) constituents at the nanometre scale, in which typically, one constituent is organic and functions as the matrix phase and the other constituent is inorganic and behaves as the filler phase. Such materials, thereby, more closely resemble natural bio-nanocomposites such as bone. Various glass compositions in combination with a wide range of natural and synthetic polymers have been evaluated in vivo under experimental conditions ranging from unloaded critical-sized defects to mechanically-loaded, weight-bearing sites with highly favourable outcomes. Additional possibilities include controlled release of anti-osteoporotic drugs, ions, antibiotics, pro-angiogenic substances and pro-osteogenic substances. Histological and morphological evaluations suggest the formation of new, highly vascularised bone that displays signs of remodelling over time. With the possibility to tailor the mechanical and chemical properties through careful selection of individual components, as well as the overall geometry (from mesoporous particles and micro-/nanospheres to 3D scaffolds and coatings) through innovative manufacturing processes, such biomaterials present exciting new avenues for bone repair and regeneration.

Shape and size complementarity induced formation of supramolecular protein assemblies with metal-oxo clusters

The controlled formation of protein supramolecular assemblies is challenging but it could provide an important route for the development of hybrid biomaterials. In this work, we demonstrate formation of well-defined complexes formed between the 8-fold symmetrical designer protein Tako8 and soluble metal-oxo clusters from the family of Anderson-Evans, Keggin and ZrIV- substituted Wells-Dawson polyoxometalates. A combination of x-ray crystallography and solution studies showed that metal-oxo clusters are able to serve as linker nodes for the bottom-up creation of protein based supramolecular assemblies. Our findings indicate that clusters with larger size and negative charge are capable of modulating the crystal packing of the protein, highlighting the need for a size and shape complementarity with the protein node for optimal alteration of the crystalline self-assembly.