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Biobased porous hydrogels enriched with phytocompounds-rich herbal extracts have aroused great interest in recent years, especially in healthcare. In this study, new macroporous hybrid cryogel constructs comprising thiourea-containing chitosan (CSTU) derivative and a Hypericum perforatumL. extract (HYPE), commonly known as St John’s wort, were prepared by a facile one-pot ice-templating strategy. Benefiting from the strong interactions between the functional groups of the CSTU matrix and those of polyphenols in HYPE, the hybrid cryogels possess excellent liquid absorption capacity, mechanical resilience, antioxidant performance, and a broad spectrum of antibacterial activity simultaneously. Thus, owing to their design, the hybrid constructs exhibit an interconnected porous architecture with the ability to absorb over 33 and 136 times their dry weight, respectively, when contacted with a phosphate buffer solution (pH 7.4) and an acidic aqueous solution (pH 2). These cryogel constructs have extremely high compressive strengths ranging from 839 to 1045 kPa and withstand elevated strains of over 70% without developing fractures. Moreover, the water-swollen hybrid cryogels with the highest HYPEcontent revealed a complete and instant shape recovery after uniaxial compression. The incorporation of HYPEinto CSTU cryogels enabled substantial improvement in scavenging reactive oxygen species and an expanded antibacterial spectrum toward multiple pathogens, including Gram-positive bacteria (Staphylococcus aureusand Staphylococcus epidermidis), Gram-negative bacteria (Escherichia coliand Pseudomonas aeruginosa), and fungi (Candida albicans). Cell viability experiments demonstrated the cytocompatibility of the 3D cryogel constructs, which did not induce changes in the fibroblast morphology. This work showcases a simple and effective strategy to immobilize HYPEextracts on CSTU 3D networks, allowing the development of novel multifunctional platforms with promising potential in hemostasis, wound dressing, and dermal regeneration scaffolds.

Tissue stroma is responsible for extracellular matrix (ECM) formation and secretion of factors that coordinate the behaviour of the surrounding cells through the microenvironment created. It’s inability to spontaneously regenerate makes it a good candidate for research studies such as testing various tissue engineered products capable of replacing the stroma in order to assure normal tissue regeneration and function. In this study, a bioactive stroma was obtained considering two main components: 1) the artificial ECM formed using atelocollagen-oxidized polysaccharides hydrogels in which the polysaccharide compound (oxidised gellan or pullulan) has the role of crosslinker and 2) encapsulated stromal cells (dermal fibroblasts, ovarian theca-interstitial and granulosa cells). The cell-hosting ability of the hydrogels is demonstrated by a good diffusion of globular proteins (albumin) while the fibrillar morphology proves to be optimal for cell adhesion. These structural properties and cytocompatibility of the components maintain good cell viability and cell encapsulation for more than 12 days. Nevertheless, the results indicate some differences favouring the gellan crosslinked hydrogels. Ovarian stromal cells functionality was maintained as indicated by hormone secretion, confirming cell–cell signalling in encapsulated and co-culture conditions. In vivoimplantation shows the regenerative potential of the cell-populated hydrogels as they are integrated into the natural tissue. The possibility of cryopreserving the hydrogel-cell system, while maintaining both cell viability and hydrogel structural integrity underlines the potential of these ready-to-use hydrogels as bioactive stroma for multipurpose tissue regeneration.

Considering its functions (support, protection, assisting in movement and storage of minerals), the bone is an essential organ for the human body and the bone trauma/damages have a great impact on the human body functionality. For that reason a variety of biomaterials are studied for potential applications in bone regeneration or substitution. Bone substitution materials, with similar chemical composition to that of natural bone, and specifically those obtained by processes which mimic the natural bone formation in vivo, has been shown to be among the best. In this study, using a process of co-precipitation of calcium phosphate precursors on a mixture of biopolymers (chitosan, collagen, hialuronic acid) and magnetic nanoparticles (magnetite functionalized with chitosan), biodegradable biomimetic scaffolds have been obtained. In order to study their chemical structure, the biodegradable scaffolds have been characterized by Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the biodegradable scaffolds, studied using scanning electron microscopy (SEM) indicated a macroporous morphology, which influenced the retention of simulated biological fluids. A direct relationship between the scaffolds’ degradation rate and the concentration of the polymeric phase has been observed. The in vitro cytocompatibility tests indicate that the prepared scaffolds are biocompatible and assure and adequate mediums for osteoblasts.

Colloidal nanosystems based on biodegradable polymeric materials that combine the capabilities of stimulus response and molecular recognition promise significant improvements in the ocular delivery of therapeutic agents.