The potent osteo-inductive capacity of bioinspired brown seaweed-derived carbohydrate nanofibrous three-dimensional scaffolds

This study aimed to investigate the osteo-inductive capacity of a fucoidan polysaccharide network derived from brown algae on human adipose-derived stem cells(HA-MSCs)for bone regeneration.The physiochemical properties of the scaffold including surface morphology,surface chemistry,hydrophilicity,mechanical stiffness,and porosity were thoroughly characterized.Both in vitro and in vivo measurements implied a superior cell viability,proliferation,adhesion,and osteo-inductive performance of obtained scaffolds compared to using specific osteogenic induction medium with increased irregular growth of calcium crystallites,which mimic the structure of natural bones.That scaffold was highly biocompatible and suitable for cell cultures.Various examinations,such as quantification of mineralization,alkaline phosphatase,gene expression,and immunocytochemical staining of pre-osteocyte and bone markers confirmed that HAD-MSCs differentiate into osteoblasts,even without an osteogenic induction medium.This study provides evidence for the positive relationship and synergistic effects between the physical properties of the decellularized seaweed scaffold and the chemical composition of fucoidan in promoting the osteogenic differentiation of HA-MSCs.Altogether,the natural matrices derived from brown seaweed offers a sustainable,cost-effective,non-toxic bioinspired scaffold and holds promise for future clinical applications in orthopedics.

Bioactive glass-based fibrous wound dressings

Since the discovery of silicate bioactive glass(BG)by Larry Hench in 1969,different classes of BGs have been researched over decades mainly for bone regeneration.More recently,validating the beneficial influence of BGs with tailored compositions on angiogenesis,immunogenicity and bacterial infection,the applicability of BGs has been extended to soft tissue repair and wound healing.Particularly,fibrous wound dressings comprising BG particle reinforced polymer nanofibers and cotton-candy-like BG fibers have been proven to be successful for wound healing applications.Such fibrous dressing materials imitate the physical structure of skin’s extracellular matrix and release biologically active ions e.g.regenerative,pro-angiogenic and antibacterial ions,e.g.borate,copper,zinc,etc.,that can provoke cellular activities to regenerate the lost skin tissue and to induce new vessels formation,while keeping an anti-infection environment.In the current review,we discuss different BG fibrous materials meant for wound healing applications and cover the relevant literature in the past decade.The production methods for BG-containing fibers are explained and as fibrous wound dressing materials,their wound healing and bactericidal mechanisms,depending on the ions they release,are discussed.The present gaps in this research area are highlighted and new strategies to address them are suggested.

Photoswitchable molecular dipole antennas with tailored coherent coupling in glassy composite

Here,we introduce the first experimental proof of coherent oscillation and coupling of photoswitchable molecules embedded randomly in a polymeric matrix and acting cooperatively upon illumination with UV light.In particular,we demonstrate the specular reflection and Brewster phenomenon alteration of photochromic molecular dipole antennas.We successfully demonstrate the concept of Brewster wavelength,which is based on the dipolar interaction between radiating dipoles and the surrounding matrix possessing a net dipole moment,as a key tool for highly localized sensing of matrix polarity.We also introduce the concept of‘tailored molecular photonic coupling’while highlighting the role of interferences for the design of optically active media by adjusting the photonic response of the medium with the real and imaginary refractive index of photoswitchable molecules in the‘ON’state.Our results enhance our fundamental understanding of coherent dipole radiation and open a new vein of research based on glassy disordered dipolar composites that act as macroscopic antenna with cooperative action;furthermore,these results have important implications for new design rules of tailored photonics.