Search Results (643)

Collagen type I has become a practical cornerstone for constructing biologically meaningful barrier interfaces in microfluidic systems. Its fibrillar architecture, native ligand display, and susceptibility to cell-mediated remodeling support epithelial and endothelial polarization, tight junctions, and transport behaviors that are difficult to achieve with purely synthetic barrier interfaces. Recent advances pair these biological strengths with tighter engineering control. For example, ultrathin collagen barriers (tens of micrometers or less) enable faster molecular exchange and short-range signaling; gentle crosslinking and composite designs limit gel compaction and delamination under flow; and patterning/bioprinting introduce alignment, graded porosity, and robust integration into device geometries. Applications now span intestine, vasculature, skin, airway, kidney, and tumor–stroma interfaces, with readouts including transepithelial/transendothelial electrical resistance (TEER), tracer permeability, and image-based quality control of fiber architecture. Persistent constraints include batch variability, long-term mechanical drift, limited standardization of fibrillogenesis conditions, and difficulties scaling fabrication without loss of bioactivity. Priorities include reporting standards for microstructure and residual crosslinker, chips for continuous monitoring, immune-competent co-cultures, and closer collaboration across materials science, microfabrication, computational modelling, and clinical pharmacology. Thus, this review synthesizes the state-of-the-art and offers practical guidance on technological readiness and future directions for using collagen type I as a biological barrier interface in biomimetic microfluidic systems. Full article

Keratoconus is a progressive, non-inflammatory corneal ectasia characterized by stromal thinning and conical protrusion. Corneal collagen cross-linking (CXL) remains the only proven treatment to halt its progression. This review compares the mechanisms, efficacy, and safety of standard (Dresden), accelerated, and transepithelial (including iontophoretic) protocols, with particular emphasis on pediatric keratoconus. Studies from PubMed, Scopus, and Web of Science were comprehensively reviewed. Standard CXL remains the gold standard due to its strong biomechanical effect and long-term stability. Accelerated protocols reduce treatment time while maintaining comparable outcomes in selected patients, though the stiffening effect may be shallower. Transepithelial and iontophoretic approaches improve comfort and reduce complications but show reduced efficacy. Future perspectives include oxygen supplementation, customized fluence modulation, and pharmacologic enhancers to improve riboflavin diffusion and oxygen availability. Full article

Protein-based hydrogels are increasingly recognized as promising biomaterials for advanced drug delivery, owing to their biocompatibility, biodegradability, and ability to recreate extracellular matrix-like environments. By tailoring the protein source, crosslinking strategy, molecular architecture, and functionalization, these hydrogels can be engineered to mimic the mechanical and biological features of native tissues. Protein-derived hydrogels are currently explored across biomedical and pharmaceutical fields, including drug delivery systems, wound healing, tissue engineering, and, notably, cancer therapy. In recent years, growing attention has been directed toward natural protein hydrogels because of their inherent bioactivity and versatile physicochemical properties. This review provides an updated overview of protein-based hydrogel classification, properties, and fabrication methods. It highlights several widely studied natural proteins, such as gelatin, collagen, silk fibroin, soy protein, casein, and whey protein, that can form hydrogels through physical, chemical, or enzymatic crosslinking. These materials offer tunable mechanical behavior, controllable degradation rates, and abundant functional groups that support efficient drug loading and the development of stimuli-responsive platforms. Furthermore, we examine current advances in their application as drug delivery systems, with particular emphasis on cancer treatment. Protein-based hydrogels have demonstrated the ability to protect therapeutic molecules, provide sustained or targeted release, and enhance therapeutic effectiveness. Although critical challenges, such as batch-to-batch variability, sterilization-induced denaturation, and the requirement for comprehensive long-term immunogenicity assessment, must still be addressed to enable successful translation from preclinical studies to clinical application, ongoing advances in the design and functionalization of natural protein hydrogels highlight their promise as next-generation platforms for precision drug delivery. Full article

Background: Keratoconus (KC) is a progressive corneal ectasia and a leading cause of corneal transplantation in young adults. Once regarded as a biomechanical disorder, KC is now recognized as a complex disease driven by genetic predisposition, epigenetic modulation, and environmental triggers. Advances in genomics and transcriptomics have begun to elucidate the molecular mechanisms underlying corneal thinning and ectasia. Objectives: This review synthesizes two decades of evidence on the genetic and epigenetic architecture of keratoconus, highlights key molecular pathways implicated by these findings, and discusses translational implications for early diagnosis, risk prediction, and novel therapeutic strategies. Methods: A narrative review was conducted of peer-reviewed human, animal, and in vitro studies published from 2000 to 2025, with emphasis on genome-wide association studies (GWAS), sequencing data, methylation profiling, and non-coding RNA analyses. Findings were integrated with functional studies linking genetic variation to molecular and biomechanical phenotypes. Results: Genetic studies consistently implicate loci such as ZNF469, COL5A1, LOX, HGF, FOXO1, and WNT10A, alongside rare variants in Mendelian syndromes (e.g., brittle cornea syndrome, Ehlers–Danlos spectrum). Epigenetic research demonstrates altered DNA methylation, dysregulated microRNAs (e.g., MIR184, miR-143, miR-182), and aberrant lncRNA networks influencing extracellular matrix remodeling, collagen cross-linking, oxidative stress, and inflammatory signaling. Gene–environment interactions, particularly with eye rubbing and atopy, further shape disease expression. Translational progress includes polygenic risk scores, tear-based biomarkers, and early preclinical studies using RNA-based approaches (including siRNA and antisense oligonucleotides targeting matrix-degrading and profibrotic pathways) and proof-of-concept gene-editing strategies demonstrated in corneal cell and ex vivo models. Conclusions: Keratoconus arises from the convergence of inherited genomic risk, epigenetic dysregulation, and environmental stressors. Integrating multi-omic insights into clinical practice holds promise for earlier detection, precision risk stratification, and development of targeted therapies that move beyond biomechanical stabilization to disease modification. Full article

The design of biomaterial scaffolds for bone tissue engineering requires a balance between bioactivity, porosity, mechanical stability, and osteoinductivity. Kappa- (KC) and iota-carrageenan (IC) have been explored for scaffold fabrication due to their biocompatibility and structural similarity to glycosaminoglycans. However, there are limited reports on how their distinct sulfation degree affects the osteogenic differentiation of cells cultured on them. While laponite has been reported as an osteoinductive nanoclay, its combined effect with different carrageenan types and its concentration-dependent effect on scaffold functionality remain unexplored. Therefore, we developed composite scaffolds comprising poly(vinyl alcohol) (PVA) and gelatin (GEL), reinforced with kappa- or iota-carrageenan (KC, IC) and functionalized with two different concentrations of laponite (LAP), 0.5 and 1% w/v, to monitor composition-structure-function relationships. The scaffolds were fabricated via lyophilization and dual crosslinking, and characterized for their physicochemical, structural, mechanical, and biological properties. The incorporation of both carrageenans into scaffolds, maintained high swelling ratios of 600% after 24 h, and increased porosity without altering their apparent density (0.09–0.11 g/cm³), whereas LAP preserved interconnectivity, densified pore walls, raised their compressive modulus at >220 kPa, and improved stability (>60% mass retained after 40 days). In vitro validation using MC3T3-E1 pre-osteoblastic cells demonstrated robust cytocompatibility, with the LAP-containing scaffolds significantly promoting cell adhesion, proliferation, and osteogenic differentiation, evidenced by elevated alkaline phosphatase activity, calcium production and collagen secretion. Direct comparison between KC and IC scaffolds confirmed that differences in sulfate substitution modulated scaffold stiffness, swelling, and degradation, while variation in LAP concentration affected the biological response, with the 0.5 wt% concentration favoring early cell proliferation, whereas the 1 wt% significantly promoted the osteogenic differentiation. This compositional strategy demonstrates how tuning the interplay between carrageenan and laponite can balance scaffold hydration, mechanical and biological properties, thereby guiding the design of scaffolds for bone repair. Full article

This study explored an eco-friendly coating system combining seagrass-derived cellulose fiber (SCF) from Cymodocea rotundata with marine type I collagen (MC) for tomato preservation. The SCF/MC composite was prepared through enzymatic and natural crosslinking processes and subsequently characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The results demonstrated that SCF/MC possessed a compact morphology, strong hydrogen bonding interactions, high crystallinity, and excellent thermal stability. When applied as a coating, SCF/MC composite significantly reduced weight loss in tomatoes, preserved firmness (>39 Units), regulated acidity, maintained moisture levels (~90%), and delayed increase in pH compared to the uncoated control. Additionally, the SCF/MC coating sustained ascorbic acid and moderated lycopene accumulation, indicating delayed ripening. At 0.5% of SCF/MC composite, spoilage was limited to 22% versus ~80% in control samples, demonstrating a substantial reduction in decay. Antifungal assay showed strong inhibition of Aspergillus flavus, with the highest suppression of mycelial growth observed at 0.5% of SCF/MC. Overall, the SCF/MC coating effectively enhanced fungal safety and maintained the physicochemical quality of tomatoes, thereby extending shelf life while valorizing seagrass biomass as a sustainable postharvest resource. Full article

Background/Objectives: Bone defects remain widespread. Type I collagen–hydroxyapatite composites suit bone engineering by mimicking matrix structure, making them pertinent materials for bone tissue engineering across a range of defect types. Their application is well aligned with non-load-bearing conditions, while use in load-bearing sites requires mechanical properties that meet the demands of those environments. Marine collagen offers a low-cost source from processing by-products. This work aimed to develop perch collagen–hydroxyapatite scaffolds for bone tissue engineering. Methods: Composites with COLL:HAp ratios of 100:0, 50:50, 40:60, and 30:70 were prepared. After crosslinking and freeze-drying, porosity and water absorption were examined. SEM and X-EDS assessed morphology and elemental distribution. FT-IR confirmed the chemical composition. Compression tests evaluated mechanical behavior. Cell viability and colonization assessed the biological performance. Biodegradability, thermal stability, and antimicrobial activity were also determined. Results: FT-IR confirmed the characteristic absorption bands of both components. SEM and swelling behavior showed porous, interconnected structures with uniform hydroxyapatite dispersion. X-EDS indicated Ca/P ratios consistent with hydroxyapatite. Thermal analysis demonstrated scaffold stability. Compression tests showed mechanical resistance for all the scaffolds, with stiffness increasing with the inorganic content. Perch collagen enhanced biological functionality, supporting osteoblast viability and colonization. Biodegradation gradually proceeded. Antibacterial activity against the tested pathogens was detectable, though moderate. Conclusions: The developed scaffolds combined structural stability, controlled degradation, and favorable cell response, constituting a viable and promising candidate for applications in bone tissue engineering. Full article

This paper proposes a potential solution to the current issue of developing advanced, biocompatible biomaterials with integrated therapeutic functionality, which would contribute to improving the treatment of skin defects. This study aimed to develop, characterize and evaluate hydrogels based on type I collagen, pectin, alginate and myrtle essential oil, in order to obtain biomaterials with potential in skin regeneration applications. Hydrogels incorporating alginate, pectin, type I collagen and Myrtus communis essential oil were prepared via a multistep procedure comprising homogenization, crosslinking and lyophilization. The obtained hydrogels were characterized by physicochemical and structural methods, such as FTIR spectroscopy, to identify interactions between components; micro-computed tomography, to evaluate internal morphology and porosity; antibacterial tests, for evaluating the ability of the hydrogel to prevent infections at the application site; and in vitro cellular tests, such as the XTT test or cytotoxicity tests, such as LDH, essential for evaluating the biocompatibility of the hydrogel. The highest viability value was recorded for sample J4 (99.53 ± 11.88%), indicating an exceptional compatibility with the cells used, almost identical to that of the untreated control. The samples showed encouraging results, supporting their potential for applications in wound treatment and skin regeneration. Full article

Background/Objectives: Burn injuries pose a significant challenge due to tissue damage and impaired healing. Cell-based therapies offer promise by delivering therapeutic cells to the wound site. However, effective cell delivery remains a critical hurdle. This study investigates the potential of non-crosslinked hyaluronic acid (HA) as a simple, versatile carrier for delivering autologous keratinocytes and fibroblasts to treat early burn wounds. Methods: Primary keratinocytes and fibroblasts were isolated from uninjured adult skin. In addition, fibroblasts and adipose stem cells (ASC) from polydactyly and progenitor fibroblasts were used. Non-cross-linked HA Redensity 1^® (RD1) solutions of varying concentrations were prepared and applied to various in vitro models. Cell viability, proliferation, migration, and collagen stimulation were assessed using standard assays. Additionally, cells were suspended in Redensity 1 and applied to an in vitro de-epidemalized dermis (DED) wound model to examine cell delivery and tissue reformation. Results: Preliminary data demonstrated the feasibility of using non-cross-linked HA RD1 gel as a cell carrier. RD1 gel enhanced cell viability, retention, migration, and collagen deposition. Histological analysis revealed improved cell adhesion and migration. Conclusions: This study provides valuable insight into the potential of non-cross-linked HA RD1 as a simple and effective delivery vehicle for cell therapies in early burn care. Successful translation of this approach could significantly improve clinical outcomes for burn patients. Full article

Inefficient chromium (III)–collagen cross-linking during leather tanning generates solid waste and effluents containing residual chromium, raising environmental and health concerns. Biological strategies are increasingly popular for tannery waste treatment, but the microbial communities involved in leather degradation remain poorly understood. This study did not seek to evaluate leather disintegration according to standardised compostability criteria, but to establish a thermophilic composting system suitable for characterising leather-associated microbial communities, biofilm formation on leather and isolating cultivable strains. Composting assays were carried out at two scales, in which wet blue leather was mixed with organic compost under self-heating thermophilic conditions. Temperature was monitored, and mass loss and changes in leather structure were determined by gravimetry and scanning electron microscopy. Bacterial and fungal communities in compost with and without leather were analysed using high-throughput amplicon sequencing. Thermophilic consortia dominated by Firmicutes, Actinobacteria and Ascomycota were established, and several bacterial isolates and a filamentous fungus were recovered. Together, these results provide a first basis for understanding the communities and strains associated with chromium-tanned leather during thermophilic composting, supporting future searches for microorganisms and enzymes of interest for biological strategies to manage chromium-tanned leather waste. Full article

Collagen-based biomaterials are widely used, but their relatively rapid biodegradation can limit functional duration. Such collagen constructs are widely used as barrier membranes in guided tissue and bone regeneration, where controlled degradation is essential for maintaining function. Although conventional crosslinking methods extend stability, they may introduce cytotoxicity, alter mechanical behavior, or hinder tissue integration. This study evaluated whether incorporating L-serine, a polar amino acid capable of hydrogen bonding, could modulate collagen structure and slow degradation without chemical crosslinking. L-Serine was selected because its hydroxyl-containing side chain can engage in biocompatible, hydrogen-bond–mediated interactions that offer a mild, non-crosslinking means of stabilizing collagen. Collagen scaffolds, prepared by incorporating L-serine into a collagen hydrogel followed by drying, were produced with 0–40 wt% L-serine and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, circular dichroism, and scanning electron microscopy. In vivo degradation was assessed in a subcutaneous mouse model comparing unmodified collagen, collagen containing 40 wt% L-serine, and a commercially available bilayer porcine collagen membrane (Bio-Gide^®, composed of type I and III collagen), with residual area quantified by serial sonography and histological evaluation. Low-to-moderate L-serine incorporation preserved triple-helical features, while 40 wt% led to crystalline domain formation and β-sheet enrichment. L-serine–treated collagen exhibited significantly greater residual area (2.70 ± 1.45 mm²) than unmodified collagen (0.37 ± 0.22 mm², p < 0.05), although Bio-Gide^® remained the most persistent (5.64 ± 2.76 mm²). These findings demonstrate that L-serine incorporation can modulate collagen structure and degradation kinetics through a simple, aqueous, and non-crosslinking approach. The results provide preliminary feasibility data supporting amino acid–assisted tuning of collagen resorption properties and justify further evaluation using membrane-specific fabrication and application-relevant testing. Full article

Background: Primary stability of dental implants depends on bone quality, bone quantity, and implant design. In cases of large defects, such as periapical lesions, the selection of an appropriate alveolar ridge preservation (ARP) material is crucial for bone regeneration and preparation for implant placement. Objective: The aim of this study was to evaluate clinical and histological outcomes of a novel ARP material hydroxyapatite and sugar cross-linked collagen (HSCC) combined with a knife-edge thread implant (KTI) design. Methods: Thirty patients were divided into two groups: a control group treated with KTI after spontaneous alveolar ridge healing, and an experimental group that underwent ARP using HSCC, and six months later, KTIs were placed in newly formed bone. Clinical parameters including insertion torque value (ITV), resonance frequency analysis (RFA), implant stability quotient (ISQ), and horizontal bone dimension were evaluated. Histological analysis was also performed. Results: No significant differences were observed between groups in ITV, ISQ, or horizontal bone dimension (p > 0.05). However, histological analysis demonstrated a significantly higher number of active osteoblasts in the ARP group compared to the control (p < 0.001), whereas collagen deposition was significantly greater in the control group (p < 0.001). Conclusions: ARP using HSCC, combined with KTI, provides favorable conditions for primary stability and successful graft integration, supporting reliable implant placement in sites with bone defects. Full article

Objective: The aim was to evaluate the effects of two high-resistance training (RT) protocols combined with curcumin supplementation on antioxidant capacity, systemic inflammation, bone and muscle health, and body composition. Methods: Eighty-one apparently healthy older adults [(68.2 ± 4.6 years (57% women); BMI 26.4 ± 4.8 kg/m²; minimally active according to IPAQ] were randomly allocated to accentuated eccentric (Aecc), maximal strength (Max), or a non-training control (C). Additionally, participants received either a bio-optimized curcumin formulation (Cur) or a placebo (Pla), resulting in six study groups: Aecc-Cur, Aecc-Pla, Max-Cur, Max-Pla, C-Cur, and C-Pla. Participants underwent pre- and post-intervention assessments of oxidative stress, inflammation, and bone health parameters, whole-body composition, and muscle function. Aecc and Max performed six familiarization sessions and a 16-week intervention. Participants in the curcumin groups received 500 mg/day of a bio-optimized curcumin formulation (Cursol^TM; 2 × 250 mg capsules per day, corresponding to 10.50 mg/day of curcumin) throughout the intervention. Data were analyzed using three-way repeated-measures ANOVA/ANCOVA with time (pre–post) as the within-subject factor and training group and supplementation as between-subject factors, with Least Significant Difference post hoc comparisons and effect sizes (Hedges’ g, ηp²) reported, and the significance level set at p < 0.05. Results: Aecc was the most effective in improving antioxidant capacity (glutathione; F = 25.57, p ≤ 0.001, ηp² = 0.262) and bone biomarkers (serum-procollagen type I N-propeptide—P1NP, p ≤ 0.001, ηp² = 0.504; serum beta C-terminal cross-linked telopeptide of type I collagen—β-CTX—p = 0.022, ηp² = 0.074, and their ratio—P1NP/β-CTX—p ≤ 0.001, ηp² = 0.605). Interleukin-6 (IL-6) decreased more in Aecc (p ≤ 0.001, ηp² = 0.584) and tumor necrosis factor-alpha (TNF-α) in Max (p ≤ 0.001, ηp² = 0.471). Both groups similarly improved body composition and muscle function. Bone mineral density was generally unchanged. Overall, curcumin supplementation enhanced the benefits of high-RT programs (further glutathione increase in Aecc [Hedge’s g: 0.49]; IL-6 decrease in both modalities [Hedge’s g: 0.48–1.27]; decrease in TNF-α in controls [Hedge’s g: 0.47]; better outcomes in P1NP/β-CTX in all groups [Hedge’s g: 0.46–1.46]; among others). Conclusions: Aecc is recommended for supporting antioxidant capacity and bone health, while the choice between Aecc and Max may depend on the individual’s inflammatory profile. Curcumin supplementation further amplifies the benefits of both RT protocols across most outcome variables. Full article

Diabetic wounds remain a major clinical challenge due to impaired angiogenesis, chronic inflammation, oxidative stress, and persistent infection, all of which delay tissue repair. Conventional dressings provide only passive protection and fail to modulate the wound microenvironment effectively. Chitosan (CS) is a naturally derived polysaccharide inspired by biological structures in crustaceans and fungi. It has emerged as a multifunctional biomimetic polymer with excellent biocompatibility, antimicrobial activity, and hemostatic properties. Recent advances in biomimetic materials science have enabled the development of stimuli-responsive CS hydrogels. These systems can sense physiological cues such as pH, temperature, glucose level, light, and reactive oxygen species (ROS). These smart systems emulate natural wound healing mechanisms and adapt to environmental changes. They release bioactive agents on demand and promote tissue homeostasis through controlled angiogenesis and collagen remodeling. This review discusses the biomimetic design rationale, crosslinking mechanism, and emerging strategies underlying single and dual-responsive hydrogel systems. It further emphasizes how nature-inspired structural and functional designs accelerate diabetic wound repair and outlines the current challenges and future prospects for translating these bioinspired intelligent hydrogels into clinical wound care applications. Full article

Inguinal hernia represents a multifactorial condition driven by extracellular matrix (ECM) dysregulation, collagen imbalance, and oxidative stress. Across studies, a consistent reduction in the collagen I:III ratio, coupled with altered expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), underpins weakened fascia and hernia susceptibility. Aging further impairs ECM remodeling through fibroblast senescence, cross-linking deficits, and elastic fiber attrition, while oxidative stress and inflammation amplify tissue degradation and impair repair mechanisms. Evidence from clinical and experimental studies underscores the interplay between surgical technique, mesh choice, redox balance, and recurrence risk. Understanding the combined impact of aging and oxidative stress provides a mechanistic framework for targeted therapeutic and surgical strategies aimed at preventing hernia development and recurrence. Full article