Chondroitin Sulfate and Hyaluronic Acid-Based PolyHIPE Scaffolds for Improved Osteogenesis and Chondrogenesis In Vitro.

Osteochondral damage, affecting the articular cartilage and the underlying subchondral bone, presents significant challenges in clinical treatment. Such defects, commonly seen in knee and ankle joints, vary from small localized lesions to larger defects. Current medical therapies encounter several challenges, such as donor shortages, drug side effects, high costs, and rejection problems, often resulting in only temporary relief. Highly porous emulsion-templated polymers (polyHIPEs) offer numerous potential benefits in the fabrication of scaffolds for tissue engineering and regenerative medicine. Polymeric scaffolds synthesized using a high internal phase emulsion (HIPE) technique, called PolyHIPEs, involve polymerizing a continuous phase surrounding a dispersed internal phase to form a solid, foam-like structure. A dense, porous design encourages cell ingrowth, nutrient delivery, and waste disposal from the scaffold, mimicking the cells' natural microenvironment. This study used hydroxyethyl methacrylate (HEMA) and acrylamide (AAM) polyHIPE scaffolds combined with extracellular matrix (ECM) components of the tissue, such as methacrylated hyaluronic acid (MHA) and methacrylated chondroitin sulfate (MCS), to prepare polyHIPE scaffolds. The mouse preosteoblast MC3T3-E1 cells and primary rat chondrocytes (harvested from male Wistar rats) were seeded on the scaffolds and cultured for 21 days to assess the osteogenesis and chondrogenesis in vitro. When compared to the AAM-MHA and AAM-MCS groups at day 21, scaffold groups HEMA-MHA and HEMA-MCS showed a significant rise in alkaline phosphatase (ALP) and calcium content. Chondrogenic markers such as glycosaminoglycan (GAG) and hydroxyproline were also assessed over a 21-day time point. On day 21, it was found that GAG and hydroxyproline production were considerably higher in the HEMA-MHA and HEMA-MCS scaffolds than in the AAM-MHA and AAM-MCS scaffolds. The overall studies showed that polyHIPE monolith scaffolds could favor cell adherence, survival ability, proliferation, differentiation, and ECM formation over 21 days. Thus, incorporating ECM components enhanced osteogenesis and chondrogenesis in vitro and can be further used as tissue repair models.

In vitro and in vivo advancement of multifunctional electrospun nanofiber scaffolds in wound healing applications: Innovative nanofiber designs, stem cell approaches, and future perspectives.

The skin is one of the most essential tissues in the human body, interacting with the outside environment and shielding the body from diseases and excessive water loss. Hydrogels, decellularized porcine dermal matrix, and lyophilized polymer scaffolds have all been used in studies of skin wound repair, wound dressing, and skin tissue engineering, however, these materials cannot replicate the nanofibrous architecture of the skin's native extracellular matrix (ECM). Electrospun nanofibers are a fascinating new form of nanomaterials with tremendous potential across a broad spectrum of applications in the biomedical field, including wound dressings, wound healing scaffolds, regenerative medicine, bioengineering of skin tissue, and multifaceted drug delivery. This article reviews recent in vitro and in vivo developments in multifunctional electrospun nanofibers (MENs) for wound healing. This review begins with an introduction to the electrospinning process, its principle, and the processing parameters which have a significant impact on the nanofiber properties. It then discusses the various geometries and advantages of MEN scaffolds produced by different innovative electrospinning techniques for wound healing applications when used in combination with stem cells. This review also discusses some of the possible future nanofiber-based models that could be used. Finally, we conclude with potential perspectives and conclusions in this area.

Phylogenetic complexities of the members of Rivulariaceae with the re-creation of the family Calotrichaceae and description of Dulcicalothrix necridiiformans gen nov., sp nov., and reclassification of Calothrix desertica.

A freshwater dwelling, tapering, heterocytous cyanobacterium (strain V13) was isolated from an oligotrophic pond in the Shrirampur taluka, Ahmednagar district of Maharashtra in India. Initial morphological examination indicated that strain V13 belonged to the genus Calothrix. Subsequent molecular and phylogenetic assessment based on 16S rRNA gene, led us to describe the freshwater/terrestrial clade of Calothrix strains without terminal hairs as a new genus Dulcicalothrix gen. nov., with the type species Dulcicalothrix necridiiformans sp. nov. (Strain V13) on the basis of the necridia forming ability of the strain. Also, the 16S-23S ITS secondary structure analysis clearly differentiated strain V13 from the other members of the clade. Past studies and the current state of knowledge makes it imperative to separate the groups Calothrix (marine/freshwater Calothrix), Macrochaete and Dulcicalothrix (freshwater/terrestrial Calothrix) into separate genera in accordance with the International Code of Nomenclature for Algae, Fungi and Plants. Robust phylogenetic evidence and previous reports strongly support the re-erection of the family Calotrichaceae distinct from the existing family Rivulariaceae.

Insights into the phylogeny of false-branching heterocytous cyanobacteria with the description of Scytonema pachmarhiense sp. nov. isolated from Pachmarhi Biosphere Reserve, India.

A false branching cyanobacterium (strain 10A1_PS) was isolated from a freshwater body of the Pachmarhi Biosphere Reserve, India and was characterised using the polyphasic approach. The detailed morphological examination indicated that the strain belonged to the complex genus Scytonema as it exhibited typical false branching character whose frequency increased with age of the culture. As the family Scytonemataceae and the genus Scytonema has been shown to be polyphyletic in many studies, we provide deep insights into the phylogenetic complexities within the family Scytonemataceae based on 16S rRNA gene phylogeny along with complete morphological, molecular and phylogenetic characterisation of the strain. The 16S rRNA gene phylogenetic tree inferred by Bayesian Inference, Neighbor-Joining and Maximum Parsimony methods showed that the strain clustered within the Scytonema sensu stricto clade. The phylogenetic distance and the positioning of the strain clearly indicated it to be different from other Scytonema species. Further analysis using rbcL phylogeny, folded secondary structures of the 16S-23S ITS, p-distance and percentage pairwise similarity matrix clearly distinguished the strain 10A1_PS from the other closely related species. In accordance with the International Code of Nomenclature for Algae, Fungi and Plants, we propose the name of the new species to be Scytonema pachmarhiense.

Description of two new species of Aliinostoc and one new species of Desmonostoc from India based on the Polyphasic Approach and reclassification of Nostoc punensis to Desmonostoc punense comb. nov.

Three heterocytous cyanobacterial strains were isolated from different habitats of Central India, and initial morphological studies indicated them to be members of the genus Nostoc or other closely related genera. Subsequent studies using morphological, ecological, molecular and phylogenetic methods indicated the three strains to be new members of the genera Aliinostoc and Desmonostoc. Folding of the D1-D1' helix of the ITS region clearly differentiated the three strains from the other closely related strains, thus providing final indications of the strains being different and new additions to the genera Aliinostoc and Desmonostoc. In accordance with the International Code of Nomenclature for algae, fungi and plants, we establish three new species: Aliinostoc tiwarii sp. nov, Aliinostoc soli sp. nov. and Desmonostoc magnisporum sp. nov. along with reclassifying Nostoc punensis as Desmonostoc punense comb. nov.