Integrated transcriptomic and proteomic study on the different molecular mechanisms of PC12 cell growth on chitosan and collagen/chitosan films

Inhibitory activity and mechanisms of chitosan against Fusarium avenaceum, a pathogen causing Angelica root rot disease

The polysaccharide chitosan possesses broad-spectrum antimicrobial properties and has proven effective in controlling various postharvest diseases in fruits. Nevertheless, the fundamental mechanisms underlying its action remain unclear. In this study, the antifungal effects of chitosan with different molecular weights against Fusarium avenaceum, a pathogen causing root rot in Angelica sinensis, were evaluated. Additionally, the potential mechanisms of these effects were explored at the microstructural and transcriptomic levels. Notably, low-molecular-weight chitosan (20 kDa) exhibited superior antifungal activity when compared to high-molecular-weight chitosan (500 kDa and 1000 kDa). The half-maximal inhibitory concentration (IC50) of 20, 500, and 1000 kDa chitosan were 0.2103, 0.2183, and 0.2707 g/L, respectively. Morphological and physiological experiments demonstrated that chitosan can inhibit the growth of F. avenaceum by decreasing spore germination, destroying mycelial morphology and microstructure, and promoting the release of intracellular electrolytes. RNA sequencing revealed considerable changes in the transcriptomic profile of F. avenaceum after chitosan treatment, with 2030 genes being differentially expressed. Subsequent KEGG pathway analysis demonstrated that genes associated with translation, human diseases, and transcription were upregulated in F. avenaceum after chitosan treatment. In contrast, genes associated with carbohydrate and amino acid metabolism, cellular processes, exogenous substance degradation and metabolism, and the metabolism of cofactors and vitamins were downregulated. Collectively, these results indicated that chitosan may influence the growth of F. avenaceum by disrupting protein biosynthesis and key metabolic pathways. These findings highlight the substantial potential of chitosan as an alternative agent for the management of fungal diseases in plants used in Chinese herbal medicine.

Biomaterials for neuroengineering: applications and challenges

Neurological injuries and diseases are a leading cause of disability worldwide, underscoring the urgent need for effective therapies. Neural regaining and enhancement therapies are seen as the most promising strategies for restoring neural function, offering hope for individuals affected by these conditions. Despite their promise, the path from animal research to clinical application is fraught with challenges. Neuroengineering, particularly through the use of biomaterials, has emerged as a key field that is paving the way for innovative solutions to these challenges. It seeks to understand and treat neurological disorders, unravel the nature of consciousness, and explore the mechanisms of memory and the brain's relationship with behavior, offering solutions for neural tissue engineering, neural interfaces and targeted drug delivery systems. These biomaterials, including both natural and synthetic types, are designed to replicate the cellular environment of the brain, thereby facilitating neural repair. This review aims to provide a comprehensive overview for biomaterials in neuroengineering, highlighting their application in neural functional regaining and enhancement across both basic research and clinical practice. It covers recent developments in biomaterial-based products, including 2D to 3D bioprinted scaffolds for cell and organoid culture, brain-on-a-chip systems, biomimetic electrodes and brain-computer interfaces. It also explores artificial synapses and neural networks, discussing their applications in modeling neural microenvironments for repair and regeneration, neural modulation and manipulation and the integration of traditional Chinese medicine. This review serves as a comprehensive guide to the role of biomaterials in advancing neuroengineering solutions, providing insights into the ongoing efforts to bridge the gap between innovation and clinical application.

Combination of gene/protein and metabolite multiomics to reveal biomarkers of nickel ion cytotoxicity and the underlying mechanism

Biomarkers have been applied for toxicity assessment of biomaterials due to their advantages. However, research on biomarkers for biomaterials is still in its early stages. There is a lack of integrated analysis in biomarker research based on multiomics studies. Herein, we report a new approach for combining of gene/protein and metabolite multiomics to reveal biomarkers of nickel ion (Ni2+) cytotoxicity and the underlying mechanism. Firstly, differentially expressed genes and proteins were compared to screen gene/protein pairs exhibiting consistent differential expression within the same Ni2+-treated groups. Next, metabolic pathway analysis was carried out to reveal pathways in which gene/protein pairs and metabolites showed upstream and downstream relationships. Important networks composed of gene/protein pairs, metabolites and metabolic pathways and candidate biomarkers were subsequently identified. Through expression level and function validation, the gene/protein/metabolite biomarkers were confirmed, and the underlying mechanism was revealed: Ni2+ influenced the expression of the Rrm2 gene biomarker, which subsequently affected the expression of the RRM2 protein biomarker. These changes in turn impacted the levels of uric acid and uridine metabolite biomarkers, ultimately inhibiting DNA synthesis, suppressing cell proliferation, increasing intracellular ROS levels and reducing ATP content.

Expression, characterization, and application potentiality evaluation of recombinant human-like collagen in Pichia pastoris

Collagen is a biofunctional protein that has been widely used in many fields, including but not limited to biomedical, cosmetics and skin care, food, and novel materials. Recombinant collagen has great potential as an alternative to collagen extracted from animals because it avoids the immune response, and the yield and properties are stable. However, challenges remain in the industrial application of recombinant collagen, including improving the expression yield, reducing the cost of purification for industry and expanding applications. In this study, a cloning and recombination method was used to heterologously express the recombinant human-like collagen (RHLC) in Pichia pastoris GS115 using the pPIC9k expression vector. The RHLC expression titre was 2.33 g/L via a 5-L fermenter, and the purification was completed within 48 h and was 98% pure. The characteristics of RHLC were investigated. Furthermore, potential applications for RHLC were explored, such as basal collagen sponge preparation, forming films with chitosan and production of collagen hydrolysed peptides. RHLC has various potential applications due to its triple helical structure, thermostability, good biocompatibility and film-forming ability.

Bone Piezoelectricity-Mimicking Nanocomposite Membranes Enhance Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells by Amplifying Cell Adhesion and Actin Cytoskeleton

Ferroelectric biomaterials have been widely investigated and demonstrated to enhance osteogenesis by simulating the inherent electrical properties of bone tissues. Nevertheless, the underlying biological processes are still not wellunderstood. Hence, this study investigated the underlying biological processes by which bone piezoelectricity-mimicking barium titanate/poly(vinylidene fluoride-trifluoroethylene) nanocomposite membranes (BTO nanocomposite membranes) promote osteogenesis of Bone Marrow Mesenchymal Stem Cells (BMSCs). Ourresults revealed that the piezoelectric coefficient (d₃₃) of nanocomposite membranes aftercontrolled corona poling was similar to that of native bone, and exhibited highly-stable piezoelectrical properties and concentrated surface electrical potential. These nanocomposite membranes significantly enhanced the adhesion and spreading of BMSCs, which was manifested as increased number and area of mature focal adhesions. Furthermore, the nanocomposite membranes significantly promoted the expression of integrin receptors genes (α1, α5 andβ3), which in turn enhanced osteogenesis of BMSCs, as manifested by upregulated Alkaline Phosphatase (ALP) and Bone Morphogenetic Protein 2 (BMP2) expression levels. Further investigations found that the Focal Adhesion Kinase (FAK)-Extracellular Signal-Regulated Kinase1/2 (ERK 1/2) signaling axis may be involved in the biological process of polarized nanocomposite membrane-induced osteogenesis. This study thus provides useful insights for betterunderstanding of the biological processes by which piezoelectric or ferroelectric biomaterials promote osteogenesis.

Metabolomics analysis of poly(l-lactic acid) nanofibers' performance on PC12 cell differentiation

The aim of this article is to reveal the influence of aligned/random poly(l-lactic acid) (PLLA) nanofibers on PC12 cell differentiation from the perspective of metabolic level. First, three materials-PLLA aligned nanofibers (PLLA AF), PLLA random nanofibers (PLLA RF) and PLLA films (control)-were prepared by electrospinning and spin coating. Their surface morphologies were characterized. Subsequently, the cell viability, cell morphology and neurite length of PC12 cells on the surface of the three materials were evaluated, indicating more neurites in the PLLA RF groups but the longer average neurite length in the PLLA AF groups. Next, the metabolite profiles of PC12 cells cultured on the surface of the three nanofibers after 12 h, 24 h and 36 h showed that, compared with the control, 51, 48 and 31 types of differential metabolites were detected at the three time points among the AF groups, respectively; and 56, 45 and 41 types among the RF groups, respectively. Furthermore, the bioinformatics analysis of differential metabolites identified two pathways and three metabolites critical to PC12 cell differentiation influenced by the nanofibers. In addition, the verification experiment on critical metabolites and metabolic pathways were performed. The integrative analysis combining cytology, metabolomics and bioinformatics approaches revealed that though both PLLA AF and RF were capable of stimulating the synthesis of neurotransmitters, the PLLA AF were more beneficial for PC12 cell differentiation, whereas the PLLA RF were less effective.