Cell Attachment Research Articles

Properties, Production, and Recycling of Regenerated Cellulose Fibers: Special Medical Applications

Regenerated cellulose fibers are a highly adaptable biomaterial with numerous medical applications owing to their inherent biocompatibility, biodegradability, and robust mechanical properties. In the domain of wound care, regenerated cellulose fibers facilitate a moist environment conducive to healing, minimize infection risk, and adapt to wound topographies, making it ideal for different types of dressings. In tissue engineering, cellulose scaffolds provide a matrix for cell attachment and proliferation, supporting the development of artificial skin, cartilage, and other tissues. Furthermore, regenerated cellulose fibers, used as absorbable sutures, degrade within the body, eliminating the need for removal and proving advantageous for internal suturing. The medical textile industry relies heavily on regenerated cellulose fibers because of their unique properties that make them suitable for various applications, including wound care, surgical garments, and diagnostic materials. Regenerated cellulose fibers are produced by dissolving cellulose from natural sources and reconstituting it into fiber form, which can be customized for specific medical uses. This paper will explore the various types, properties, and applications of regenerated cellulose fibers in medical contexts, alongside an examination of its manufacturing processes and technologies, as well as associated challenges.

Translational implications of a novel combination of iPRF and collagen scaffold for proliferation of gingival mesenchymal stem cells.

"Tissue engineering," is a concept that involves the use of scaffolds, cells, and growth factors/signaling molecules in the field of regenerative medicine. The present study was carried out to evaluate the attachment and depth of penetration of the Gingival Mesenchymal Stem Cells (GMSCs) onto the collagen scaffold preconditioned with Fetal Bovine Serum (FBS), Injectable Platelet Rich Fibrin (i-PRF) and a combination of FBS with i-PRF using histological analysis and environmental scanning electron microscopy (ESEM) respectively. In the present study, commercially available collagen membranes were used as scaffolds and divided into 3 groups where Group I was preconditioned with FBS, Group II was preconditioned with i-PRF, and Group III with a combination of FBS and i-PRF. Scaffolds were then seeded with GMSCs and incubated in a CO2 incubator at 37 0C for 7 days. Both histological and ESEM analysis showed proliferation, attachment, and depth of penetration along with the combination of cell morphological changes in all the three groups. In group I cells showed mild depth of penetration along with a round morphological appearance. In group II the cells showed moderate depth of penetration and rounded morphology. In group III maximum depth of penetration was seen along with the round and spheroidal morphology of cells. The combination of the growth media showed the best effect on cell attachment, depth of penetration, and cell morphology. This is the first report demonstrating the effect of the combination of collagen and i-PRF supports the proliferation of GMSCs. Since FBS alone and i-PRF alone exhibited similar cell proliferation it is recommended that i-PRF could be used in clinical scenarios making it xenofree.

Cell Adhesion and Local Cytokine Control on Protein-Functionalized PNIPAM-co-AAc Hydrogel Microcarriers.

Achieving adequate cell densities remains a major challenge in establishing economic biotechnological and biomedical processes. A possible remedy is microcarrier-based cultivation in stirred-tank bioreactors (STBR), which offers a high surface-to-volume ratio, appropriate process control, and scalability. However, despite their potential, commercial microcarriers are currently limited to material systems featuring unnatural mechanical properties and low adaptability. Because matrix stiffness and ligand presentation impact phenotypical attributes, differentiation potential, and genetic stability, biotechnological processes can significantly benefit from microcarrier systems tailorable toward cell-type specific requirements. This study introduces hydrogel particles co-polymerized from poly(N-isopropylacrylamide) (PNIPAM) and acrylic acid (AAc) as a platform technology for cell expansion. The resulting microcarriers exhibit an adjustable extracellular matrix-like softness, an adaptable gel charge, and functional carboxyl groups, allowing electrostatic and covalent coupling of cell adhesive and cell fate-modulating proteins. These features enable the attachment and growth of L929 mouse fibroblast cells in static microtiter plates and dynamic STBR cultivations while also providing vital growth factors, such as interleukin-3, to myeloblast-like 32D cells over 20 days of cultivation. The study explores the effects of different educt compositions on cell-particle interactions and reveals that PNIPAM-co-AAc microcarriers can provide both covalently coupled and diffusively released cytokine to adjacentcells.

Optimizing scaffold pore size for tissue engineering: insights across various tissue types

Scaffold porosity is a critical factor in replicating the complex in vivo microenvironment, directly influencing cellular interactions, migration, nutrient transfer, vascularization, and the formation of functional tissues. For optimal tissue formation, scaffold design must account for various parameters, including material composition, morphology, mechanical properties, and cellular compatibility. This review highlights the importance of interconnected porosity and pore size, emphasizing their impact on cellular behavior and tissue formation across several tissue engineering domains, such as skin, bone, cardiovascular, and lung tissues. Specific pore size ranges enhance scaffold functionality for different tissues: small pores (∼1–2 µm) aid epidermal cell attachment in skin regeneration, moderate pores (∼2–12 µm) support dermal migration, and larger pores (∼40–100 µm) facilitate vascular structures. For bone tissue engineering, multi-layered scaffolds with smaller pores (50–100 µm) foster cell attachment, while larger pores (200–400 µm) enhance nutrient diffusion and angiogenesis. Cardiovascular and lung tissues benefit from moderate pore sizes (∼25–60 µm) to balance cell integration and nutrient diffusion. By addressing critical design challenges and optimizing pore size distributions, this review provides insights into scaffold innovations, ultimately advancing tissue regeneration strategies.

Tailoring Cell Attachment onto Melt Electrowritten Scaffolds via a Phase Separated Hydrogel Coating with Peptide Functionalization

AbstractHighly porous scaffolds with a high surface area can be designed and fabricated via melt electrowriting (MEW). Here, the study introduces morphological features onto the MEW microfibers via a hydrogel coating of phase‐separated poly(2‐hydroxyethyl methacrylate) (pHEMA). This coating is achieved by capturing phase‐separated droplets of pHEMA onto poly(ε‐caprolactone) (PCL) microfibers via dip‐coating, resulting in a hydrogel coating with webbed structures across pores of the MEW scaffold. Excess pHEMA droplets are removed and phase separation is quenched by washing in water, and then functionalized by dipping the pHEMA coated scaffold into a buffered peptide solution. It is demonstrated that a cysteine‐terminated peptide sequence (Cys‐Gly‐Arg‐Gly‐Asp‐Ser‐Gly (CG‐RGD‐SG)) promotes fibroblast adhesion on the hydrogel‐coated MEW scaffolds compared to unmodified pHEMA and compared to scrambled peptide sequence. Due to the protein‐resistant nature of pHEMA, the hydrogel‐coated scaffolds show less cell attachment than non‐coated PCL scaffolds, while RGD‐functionalized pHEMA scaffolds achieve 2.8‐fold increase in cell attachment (p = 0.02) when compared to non‐functionalized pHEMA. The study therefore presents a platform that combines PCL scaffolds of microscale fibers with a phase‐separated pHEMA hydrogel coating that maintains the high porosity of MEW scaffolds yet increases surface area and, importantly, introduces the capability for tailoring cell attachment via peptide functionalization.

Thymoquinone-Incorporated CollaGee Biomatrix: A Promising Approach for Full-Thickness Wound Healing

Wound infection is the leading cause of delayed wound healing. Despite ongoing research, the ideal treatment for full-thickness skin wounds is yet to be achieved. Skin tissue engineering provides an alternative treatment, with the potential for skin regeneration. Background/Objectives: Previously, we characterized a collagen–gelatin–elastin (CollaGee) acellular skin substitute and evaluated its cytocompatibility. The assessments revealed good physicochemical properties and cytocompatibility with human dermal fibroblasts (HDF). This study aimed to incorporate thymoquinone (TQ) as the antibacterial agent into CollaGee biomatrices and evaluate their cytocompatibility in vitro. Methods: Briefly, dose–response and antibacterial studies were conducted to confirm the antimicrobial activity and identify the suitable concentration for incorporation; 0.05 and 0.1 mg/mL concentrations were selected. Then, the cytocompatibility was evaluated quantitatively and qualitatively. Results: Cytocompatibility analysis revealed no toxicity towards HDFs, with 81.5 + 0.7% cell attachment and 99.27 + 1.6% cell viability. Specifically, the 0.05 mg/mL TQ concentration presented better viability, but the differences were not significant. Immunocytochemistry staining revealed the presence of collagen I, vinculin, and alpha smooth muscle actin within the three-dimensional biomatrices. Conclusions: These results suggest that TQ-incorporated CollaGee biomatrices are a promising candidate for enhancing the main key player, HDF, to efficiently regenerate the dermal layer in full-thickness skin wound healing. Further investigations are needed for future efficiency studies in animal models.

TMOD-29. BETA INTEGRINS REGULATE MITOCHONDRIALLY-MEDIATED CELL MIGRATION IN H3K27M-DIFFUSE MIDLINE GLIOMA

Abstract Infiltration into the brain tissue is one of the main features of diffuse midline gliomas (DMG), also characterized by the histone mutation H3K27M and overall survival of 12-15 months from diagnosis. To study which genes are critical for H3K27M-DMG tumor cell migration in the brain, we established a novel two-step pooled whole genome CRISPR-Migration screen of metastatic H3K27M-DMG (n=3) and glioblastoma (GBM, n=2) stem cells by using serum-free conditions and laminin-dependent cell attachment, mimicking cell migration on brain vasculature scaffolds. Genes involved in focal adhesion (ITGB1, CRKL, PARVA, PTK2, FERMT2) were identified as significantly restricting migration in all H3K27M-DMG lines. From those, only knockout of ITGB1 (ITGB1-KO) fully ablated in vitro migration in all models. In human tumor RNAseq, expression of ITGB1 correlated with higher glioma grade and worse survival specifically in H3K27M-DMG across pediatric brain tumors. In H3K27M-DMG scRNAseq, increased ITGB1 expression was found in cells with OPC-like/Mesenchymal cell signature associated with leading edge and microvasculature. Unexpectedly, ITGB1-KO led to the decreased expression of multiple mitochondrial NADH dehydrogenase genes, and reduced levels of glycolysis and oxidative phosphorylation (OXPHOS) activity. Preliminary mechanistic data linked this phenotype to increased mitochondrial fusion. Genetic (ITGB1-KO) and pharmacologic (anti-ITGB1 antibody AIIB2, CNS delivered) targeting of ITGB1 in a novel orthotopic model of metastatic H3K27M-DMG (UMPED83) led to reduced proliferation and significant extension of survival (p=0.0003 ITGB1-KO, and p=0.0006 AIIB2). Interestingly, ITGB1-KO in another orthotopic H3K27M-DMG model (SVZ) led to upregulation of other integrins (ITGB3 and ITGB5) without change in survival, resulting in susceptibility to treatment with the ITGB3/5 inhibitor Cilengitide (p=0.006). Treatment with AIIB2 and Cilengitide alone or in combination was ineffective in an H3WT adult GBM orthotopic model suggesting unique H3K27M-DMG targetability. In summary, targeting of integrin pathways offers untapped therapeutic opportunities in H3K27M-DMG by impairing tumor cell survival through altered mitochondrial dynamics.

BIOM-06. NOGGIN CONTRIBUTES TO BRAIN METASTATIC COLONIZATION OF LUNG CANCER CELLS

Abstract Brain metastasis is a common complication among patients with lung cancer, yet the underlying mechanisms remain unclear. In this study, we aimed to investigate the pathogenesis of brain metastasis in lung cancer. We established highly colonizing metastatic lung cancer cells, A549-M2, through multiple implantations of A549 human lung cancer cells in the carotid artery of athymic nude mice. Compared to parental cells (M0), M2 cells demonstrated slower growth in culture plates and soft agar, as well as lower motility and higher adhesion, key characteristics of mesenchymal-epithelial transition (MET). Further analysis revealed that M2 cells exhibited decreased expression of epithelial-mesenchymal transition markers, including ZEB1 and Vimentin. M2 cells also demonstrated reduced invasiveness in co-culture systems. RNA sequencing and gene set enrichment analysis confirmed that M2 cells underwent MET. Intriguingly, depletion of Noggin, a BMP antagonist, was observed in M2 cells, and replenishment of Noggin restored suppressed migration and invasion of M2 cells. In addition, Noggin knockdown in control M0 cells promoted cell attachment and suppressed cell migration, suggesting that Noggin reduction during brain colonization causes inhibition of migration and invasion of metastatic lung cancer cells. Our results suggest that lung cancer cells undergo MET and lose their motility and invasiveness during brain metastatic colonization, which is dependent on Noggin.

Role of intermediate water in alleviating postsurgical intrapericardial adhesion.

Various polymers have been used as postsurgical antiadhesive materials; however, the mechanisms underlying their efficacy remain unclear. Intermediate water has been found to prevent the adhesion between polymer molecules and proteins or cells. The present study investigated the role of intermediate water retained in the polymer in alleviating postsurgical pericardial adhesion. Hydrophobic fabrics were prepared using biodegradable polyglycolic acid. To add intermediate water, the fabric fibers were coated with poly(oxyethylene)oleyl ethers. Intermediate water in the hydrated state was detected by a thermal analysis for each material, and cell attachment to the fibers with or without coating was observed in vitro. Using a canine model of postsurgical pericardial adhesion, the severity of adhesion was examined along with a histological assessment during treatment, with or without fabric coating. Intermediate water was detected in the coating materials but not in polyglycolic acid. Coating significantly reduced the cell attachment to the fibers. Coating also alleviated adhesion by reducing inflammation in the fibrous layer and replacing the fabric and granulomas that develop around the surgical sutures in the pericardial space. Intermediate water in the hydrated polymer of anti-adhesives may play an important role in alleviating postoperative pericardial adhesion.

Innovative spiral nerve conduits: Addressing nutrient transport and cellular activity for critical-sized nerve defects

Large-gap nerve defects require nerve guide conduits (NGCs) for complete regeneration and muscle innervation. Many NGCs have been developed using various scaffold designs and tissue engineering strategies to promote axon regeneration. Still, most are tubular with inadequate pore sizes and lack surface cues for nutrient transport, cell attachment, and tissue infiltration. This study developed a porous spiral NGC to address these issues using a 3D-printed thermoplastic polyurethane (TPU) fiber lattice. The lattice was functionalized with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) electrospun aligned (aPHBV) and randomly (rPHBV) oriented nanofibers to enhance cellular activity. TPU lattices were made with 25 %, 35 %, and 50 % infill densities to create scaffolds with varied mechanical compliance. The fabricated TPU/PHBV spiral conduits had significantly higher surface areas (25 % TPU/PHBV: 698.97 mm2, 35 % TPU/PHBV: 500.06 mm2, 50 % TPU/PHBV: 327.61 mm2) compared to commercially available nerve conduits like Neurolac™ (205.26 mm2). Aligned PHBV nanofibers showed excellent Schwann cell (RSC96) adhesion, proliferation, and neurogenic gene expression for all infill densities. Spiral TPU/PHBV conduits with 25 % and 35 % infill densities exhibited Young's modulus values comparable to Neurotube® and ultimate tensile strength like acellular cadaveric human nerves. A 10 mm sciatic nerve defect in Wistar rats treated with TPU/aPHBV NGCs demonstrated muscle innervation and axon healing comparable to autografts over 4 months, as evaluated by gait analysis, functional recovery, and histology. The TPU/PHBV NGC developed in this study shows promise as a treatment for large-gap nerve defects.

Formation of a giant unilocular vacuole via macropinocytosis-like process confers anoikis resistance

Cell survival in metazoans depends on cell attachment to the extracellular matrix (ECM) or to neighboring cells. Loss of such attachment triggers a type of programmed cell death known as anoikis, the acquisition of resistance to which is a key step in cancer development. The mechanisms underlying anoikis resistance remain unclear, however. The intracellular F-actin cytoskeleton plays a key role in sensing the loss of cell–ECM attachment, but how its disruption affects cell fate during such stress is not well understood. Here, we reveal a cell survival strategy characterized by the formation of a giant unilocular vacuole (GUVac) in the cytoplasm of the cells whose actin cytoskeleton is disrupted during loss of matrix attachment. Time-lapse imaging and electron microscopy showed that large vacuoles with a diameter of >500 nm accumulated early after inhibition of actin polymerization in cells in suspension culture, and that these vacuoles subsequently coalesced to form a GUVac. GUVac formation was found to result from a variation of a macropinocytosis-like process, characterized by the presence of inwardly curved membrane invaginations. This phenomenon relies on both F-actin depolymerization and the recruitment of septin proteins for micron-sized plasma membrane invagination. The vacuole fusion step during GUVac formation requires PI(3)P produced by VPS34 and PI3K-C2α on the surface of vacuoles. Furthermore, its induction after loss of matrix attachment conferred anoikis resistance. Our results thus show that the formation of a previously unrecognized organelle promotes cell survival in the face of altered actin and matrix environments.

Formation of a giant unilocular vacuole via macropinocytosis-like process confers anoikis resistance.

Cell survival in metazoans depends on cell attachment to the extracellular matrix (ECM) or to neighboring cells. Loss of such attachment triggers a type of programmed cell death known as anoikis, the acquisition of resistance to which is a key step in cancer development. The mechanisms underlying anoikis resistance remain unclear, however. The intracellular F-actin cytoskeleton plays a key role in sensing the loss of cell-ECM attachment, but how its disruption affects cell fate during such stress is not well understood. Here, we reveal a cell survival strategy characterized by the formation of a giant unilocular vacuole (GUVac) in the cytoplasm of the cells whose actin cytoskeleton is disrupted during loss of matrix attachment. Time-lapse imaging and electron microscopy showed that large vacuoles with a diameter of >500 nm accumulated early after inhibition of actin polymerization in cells in suspension culture, and that these vacuoles subsequently coalesced to form a GUVac. GUVac formation was found to result from a variation of a macropinocytosis-like process, characterized by the presence of inwardly curved membrane invaginations. This phenomenon relies on both F-actin depolymerization and the recruitment of septin proteins for micron-sized plasma membrane invagination. The vacuole fusion step during GUVac formation requires PI(3)P produced by VPS34 and PI3K-C2α on the surface of vacuoles. Furthermore, its induction after loss of matrix attachment conferred anoikis resistance. Our results thus show that the formation of a previously unrecognized organelle promotes cell survival in the face of altered actin and matrix environments.

Drug-Eluting and Antibacterial Core-Shell Polycaprolactone/Pectin Nanofibers Containing Ti3C2Tx MXene and Medical Herbs for Wound Dressings.

Fibrous scaffolds capable of delivering natural drugs and herbs show great promise for tissue regeneration and wound care, particularly in personalized medicine. This study presents the fabrication and characterization of drug-eluting antibacterial core-shell mats composed of polycaprolactone (PCL) and pectin nanofibers produced through coaxial electrospinning. Berberine chloride (BBR), an herbal compound with antineoplastic, anti-inflammatory, antilipidemic, and antidiabetic properties, served as the model drug. Poly(vinyl alcohol) (PVA) was blended with pectin to enhance the mechanical properties of the core fibers. The shell was modified with two-dimensional Ti3C2Tx (MXene) nanosheets and subjected to covalent and ionic cross-linking. Structural analysis confirmed the successful production of bead-free fibers with diameters ranging from 160 to 350 nm, depending on composition. The PCL core fibers were uniformly coated with a pectin/PVA shell approximately 90 nm thick. The inclusion of BBR and MXene increased the fiber diameter. Drug-release kinetics, modeled by using Korsmeyer-Peppas, revealed a two-stage release mechanism. An initial burst release occurred within the first 24 h (kinetic exponent n = 1.36), followed by sustained release over 2 weeks (n = 0.48). The release mechanisms were identified as case-II relaxational release in the first stage, transitioning to quasi-Fickian diffusion in the second. Incorporating MXene into the shell further prolonged drug release. The mechanical strength of the scaffolds improved significantly by a factor of 7 and 4 in wet and dry conditions, respectively. In vitro biocompatibility assays using L929 cells demonstrated excellent cell attachment and compatibility. Additionally, antibacterial tests against Escherichia coli showed that the inclusion of MXene enhanced antibacterial activity by 30%. These results suggest that the functional biocomposite scaffolds hold the potential for developing innovative, drug-eluting wound dressings.

Application of Alginate-Collagen Hydrogel and Its Related Mechanisms in the Repair of Rat Cartilage Injuries

This research investigated the application of alginate-collagen hydrogel (ACH) in rat cartilage injury (CI) repair and its related mechanisms through in vitro and in vivo experiments. Alginate solution and modified collagen solution were mixed to prepare the ACH. The obtained samples were characterized and their sustained release properties were determined. L929 mouse fibroblasts were assigned into a blank control group (BC group, untreated), a positive control group (PC group, treated with 6.4% phenol), a negative control group (NC group, treated with tissue culture polystyrene), and an ACH group (treated with ACH). Cell viability was assessed using the MTT assay. Meanwhile, the cytotoxicity of the ACH and its impact on cell proliferation and cell attachment capabilities were analyzed. Thirty 4-week-old specific pathogen-free (SPF) Sprague Dawley (SD) rats were randomly grouped into a chondrocyte group (5 rats, chondrocytes collected and cultured), a cPAGE group (5 rats, chondrocytes treated with ACH), a model group (10 rats, CI model), and a mPAGE group (10 rats, CI model treated with CAH). The influence of CAH on chondrocyte proliferation and the type II collagen (COLII) expression were assessed using the cell counting kit 8 (CCK-8) assay and immunofluorescence staining. Furthermore, the impacts of CAH on chondrocyte tissue and COL-II expression were analyzed using Safranin O-Fast Green (SOFG) staining, the International Cartilage Repair Society (ICRS) score, and COL-II tissue staining. Immunoblotting was utilized to detect the TNF-α, NF-κB, matrix metalloproteinase 13 (MMP-13), and COL-II proteins in cartilage tissue. The results showed that release rate (RR) of the constructed ACH reached over 85% within 72 hours and achieved degradation equilibrium within 5 days with a weight loss (WL) rate of over 60%. L929 fibroblasts culture results showed that the ACH posed no significant cytotoxicity, and cell attachment results were not obviously different from those on tissue culture plates (P >0.05). MTT assay results demonstrated that the ACH exerted no adverse effects on L929 cell proliferation and growth, indicating a good biocompatibility. CCK-8 and COL-II results indicated that chondrocyte proliferation in cPAGE group was much higher in contrast to that in chondrocyte group (P <0.05). Besides, the animal experiments unveiled that in comparison to the CI group, the mPAGE group had more chondrocytes, upregulated COL-II, and higher ICRS scores (P <0.05). MMP-13, NF-κB, and TNF-α were downregulated, and COL-II was upshifted in the mPAGE group, with remarkable differences (P <0.05). In conclusion, ACH exhibited excellent biocompatibility and low cytotoxicity, promoted cell proliferation and growth, facilitated chondrocyte proliferation in rat CI repair, offering a valuable research foundation for CI treatment.

Mussel-inspired modified regenerated cellulose as tissue adhesive and antibacterial gauze: A promising approach for rapid hemostasis in non-compressible hemorrhage

Uncontrollable hemorrhage leads to high mortality rates; thus, engineering effective hemostatic materials is crucial for rapid hemostasis. Developing hemostatic materials for rapid coagulation, antibacterial activity, and easy removal without compromising clot integrity remains a challenge. Herein, a multifunctional hemostatic gauze was engineered by modifying regenerated cellulose textile through multiple sequential chemical reactions, including carboxymethylation, crosslinking with CaCl2/ZnCl2 solution, oxidation, and polymerization with dopamine. Provided gauze demonstrated remarkable wet-tissue adhesion (890 kPa) that physically sealing the area to prevent blood loss. The engineered gauze exhibits excellent antibacterial activity (against S. aureus and E. coli) and enhanced hemostatic ability (clotting time (20S), attachment of red blood cells (~93 %) and platelets (~80 %)). The complete hemostasis and stable clot formation without secondary bleeding were achieved by synthesized gauze in 20s, 50s, and 100s for the rat and rabbit liver, and rat femoral artery injury models, respectively. That was significantly faster hemostasis (4–14-fold reduction in time) and lower blood loss (3-fold reduction) compared to the commercial hemostatic textiles (p < 0.001). Biochemical, hematological, and pathological examinations revealed no evidence of systemic and local inflammation or toxic effects in the rat organs. The engineered hemostatic gauze exhibits outstanding characteristics of a hemostatic material for clinical applications.

Hydroxyapatite/Chondroitin Sulphate Nanocomposite Infused with Black Seed Oil for Bone Tissue Applications: Physicochemical Characterizations and In Vitro Screening

AbstractMorbidities associated with natural bone have highlighted the need of advanced bioactive implants for the replacement of damaged bone. Known for their beneficial bioactivity and biocompatibility, Nigella sativa seeds (kalonji/black seed) are traditionally used in many medications. This research focuses on the positive impact of black seed extract on the chondroitin sulfate‐based hydroxyapatite nanocomposite for bone tissue regeneration applications. Novel nanocomposites with varied concentrations of black seed extract (0, 1, 2, and 3 wt%) were fabricated through a coprecipitation approach and analyzed for physicochemical and biological applications. The results of X‐ray diffraction and FTIR spectroscopy revealed that the HCSK3 nanocomposite was successfully developed with appreciably strong molecular interactions among their components. HCSK3 nanocomposite exhibits higher rough surface morphology (Ra −1.13 µm and Rz −4.8 µm), uniform particle distribution (average particle size −9.9 nm), and good thermal stability with total weight loss of 13%. It also provides better nucleation sites for apatite formation and protein adsorption stimulating cell attachment, proliferation, and differentiation. Moreover, HCSK3 nanocomposite showed excellent cell viability, higher ARS/ALP activities, better antibacterial property, and nonhemolytic property (below 3%). Thus, it can be concluded that HCSK3 nanocomposite manifested the highest biocompatibility and negligible cell toxicity. Therefore, it can be employed as an ideal bone implant in the bone tissue restoration phenomenon.

Design and preparation of biomimetic "Hard-soft" functional scaffold with gradient irregular pore structure for bone repair

To treat critical-sized defects in long bones, a novel structure was proposed by introducing a Haversian biomimetic structure and trabecular-like irregular pore morphology (IPM) structure into functional gradient porous scaffolds (FGPS). The outer shell structure is a "hard" structure providing mechanical support, and the inner core is a "soft" structure with radial gradient distribution IPM structure to promote the ingrowth of bone tissue. In this study, different inner core continuous gradient FGPS (GIPM) and layered FGPS (IPM, and BCC structure), with different outer shell pore sizes (300, 500, and 700 μm) were designed and fabricated by selective laser melting. The results show the stiffness of those FGPS was between 20.0-28.7 kN/mm, which is similar to the native femur (with a stiffness ranging from 7.2-11.7 kN/mm) of similar size. The GIPM-500 has more uniform stress distribution and stress transfer, resulting in superior load-bearing efficiency. Moreover, GIPM-500 exhibited excellent fatigue durability, achieving excellent fatigue cycles of more than 1×106 cycles. Cell immunofluorescence shows that the GIPM-500 and IPM-500 are more suitable for cell attachment and growth due to the flexibility of the local porosity and curvature. Bone defect repair simulations showed that GIPM-500 can meet normal load-bearing requirements while having little impact on the normal stress-strain trajectory. This work provides a novel biomimetic scaffold design containing both cortical and trabecular bone components for repairing critical-size defects in long bones.

Development of liposomal amniotic mesenchymal stem cell metabolite products (AMSC-MP) loaded-scaffold for in vitro osteogenesis induction

The use of scaffolds with good biocompatibility and mechanical properties largely determines the success of bone defect therapy intended to improve quality-adjusted life years. Furthermore, amniotic mesenchymal stem cell metabolite product (AMSC-MP) is required to accelerate bone regeneration with sustained release required to maximize the effectiveness of therapy. This study aims to evaluate the effect of different phospholipids on the osteogenesis capacity of AMSC-MP liposome loaded into scaffold. The thin layer hydration method was employed to create the AMSC-MP liposomes which had different lipid components: L-α-phosphatidylcholine (PC) an unsaturated or hydrogenated soybean phosphatidylcholine (HSPC), a saturated phospholipid, with different types of charged phospholipids i.e., 1,2-dioleoyltrimethylammoniumpropane (DOTAP) or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), which were cationic and non-ionic lipids respectively.AMSC-MP liposomes were embedded in the scaffold during a 24-hour incubation period. The results indicated that the particle sizes of liposomes prepared with saturated phospholipids, HS-DOTAP (132.35 ± 2.75 nm) and HS-DOTAP (152.85 ± 5.86 nm) were larger than those with saturated phospholipids, namely PC-DOTAP (139.355 ± 2.75 nm) and PC-DOTAP (91.85 ± 0.07 nm). The use of DOTAP in AMSC-liposomes resulted in positively charged vesicles i.e., +5 mV for HSPC-DOTAP and + 10 mV for PC-DOTAP. Moreover, the results of an MTT viability test conducted on 7f2 cells and MSC indicated that all the formulas demonstrate good in vitro biocompatibility. Formulations containing DOPE produced high cellular uptake values and had superior sustain release properties compared to the others. This result correlates positively with cell attachment to the liposome scaffold which was higher than the others. Moreover, DOPE-containing formulations increased RUNX2 expression, indicating enhanced in vitro osteogenesis capacity. Therefore, Liposome AMSC-MP loaded scaffold demonstrates high potential for use in bone regeneration therapy.

Targeting ovarian cancer cell attachment to the peritoneum

Targeting ovarian cancer cell attachment to the peritoneum

Soft, precision engineered porous, hydrogel scaffolds mechanically tailored toward applications in the central nervous system

Diseases and traumatic injuries to the central nervous system (CNS) demand the development of new biomaterials to improve healing and treatment options. Matching material mechanical properties to specific tissues and optimizing material porous structures are central goals for improving biomaterials. However, biomaterials with both precision-controlled porous structures and brain-matched mechanical properties (low modulus) are still lacking. In this study, we developed soft hydrogel scaffolds with mechanical properties similar to that of CNS tissues, and a uniform 40 µm porous structure—40 µm pores have been shown to be optimal for healing in many tissues. The two characteristics were achieved by a new fabrication process combining phase separation and sphere templating. The resulting scaffolds are non-cytotoxic according to the ISO 10993-5 standard. In addition, the three-dimensional culture of microglial cells within the scaffolds demonstrates cell attachment and maintenance of a rounded, quiescent morphology, potentially due to spatial confinement. These results justify further in vivo studies and suggest broad potential in CNS applications, such as brain-computer interfaces, neural regeneration, and basic neurobiology. Subject classification codes: Neural Interfaces, soft hydrogel, synthetic biomaterials