Anti-citrullinated α-enolase peptide as a highly sensitive autoantigen in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) is the most common autoimmune rheumatic disease in Taiwan. Anti-cyclic citrullinated peptide (anti-CCP) assay is widely used for RA diagnosis; however, not all anti-CCPs are detectable in RA-joint lesions. Citrullinated α-enolase peptide (CEP), which has a unique immunodominant epitope, can be detected in synovial fluid. Here, we aimed to evaluate the potential of anti-CEP as a serologic marker for the early diagnosis of RA and a prognostic predictor of joint destruction. We also determined the association of single-nucleotide polymorphisms (SNPs) in genes with the serological status and clinical characteristics of RA. Clinical records of 30 patients with RA were collected, and their serum and DNA samples were evaluated using enzyme-linked immunosorbent assay (ELISA) and SNP cross-reaction analysis. A considerable amount of anti-CEP was detected in patients with RA, a trend similar to that of anti-CCP. Moreover, anti-CEP was considerably associated with the protein-arginine deiminase type-2 SNP rs1005753.

The Potential of Glucose Treatment to Reduce Reactive Oxygen Species Production and Apoptosis of Inflamed Neural Cells In Vitro.

Neuroinflammation is a key feature in the pathogenesis of entrapment neuropathies. Clinical trial evidence suggests that perineural injection of glucose in water at entrapment sites has therapeutic benefits beyond a mere mechanical effect. We previously demonstrated that 12.5-25 mM glucose restored normal metabolism in human SH-SYFY neuronal cells rendered metabolically inactive from TNF-α exposure, a common initiator of neuroinflammation, and reduced secondary elevation of inflammatory cytokines. In the present study, we measured the effects of glucose treatment on cell survival, ROS activity, gene-related inflammation, and cell cycle regulation in the presence of neurogenic inflammation. We exposed SH-SY5Y cells to 10 ng/mL of TNF-α for 24 h to generate an inflammatory environment, followed by 24 h of exposure to 3.125, 6.25, 12.5, and 25 mM glucose. Glucose exposure, particularly at 12.5 mM, preserved apoptotic SH-SY5Y cell survival following a neuroinflammatory insult. ROS production was substantially reduced, suggesting a ROS scavenging effect. Glucose treatment significantly increased levels of CREB, JNK, and p70S6K (p < 0.01), pointing to antioxidative and anti-inflammatory actions through components of the MAPK family and Akt pathways but appeared underpowered (n = 6) to reach significance for NF-κB, p38, ERK1/2, Akt, and STAT5 (p < 0.05). Cell regulation analysis indicated that glucose treatment recovered/restored function in cells arrested in the S or G2/M-phases. In summary, glucose exposure in vitro restores function in apoptotic nerves after TNF-α exposure via several mechanisms, including ROS scavenging and enhancement of MAPK family and Akt pathways. These findings suggest that glucose injection about entrapped peripheral nerves may have several favorable biochemical actions that enhance neuronal cell function.

Low Molecular Weight Sericin Enhances the In Vitro of Immunological Modulation and Cell Migration.

Sericin, a waste product of the silk textile industry, has favorable physicochemical and biological properties. In this study, we extracted a low molecular weight (MW) sericin (LMW-sericin; below 10 kDa) by a performing high-temperature and high-pressure method and confirmed the MW using matrix-assisted laser desorption ionization-time of flight and liquid chromatography-mass spectrometry. Furthermore, we determined its biological effects on macrophages and human adipose stem cells (hASCs) as cell models to investigate the biocompatibility, immunomodulation behavior, and potential signaling pathway-related wound healing via analyses of gene expression of focal adhesion and human cytokines and chemokines using quantitative real-time polymerase chain reaction and cytokine assay. LMW-sericin showed good biocompatibility both in macrophages and hASCs. Macrophages cultured with 0.1 mg/ml LMW-sericin displayed an improved inflammatory response shown by the upregulation of CXCL9, IL12A, BMP7, and IL10, which developed Th1 and Th2 balance. LMW-sericin also improved the differentiation of macrophages toward the M2 phenotype by significantly enhancing the expression of Arg-1, which is conducive to the repair of the inflammatory environment. Moreover, the gene expression of hASCs showed that LMW-sericin promoted the secretion of beneficial adhesion molecules that potentially activate the gene transcription of differentiation and migration in hASCs, as well as significantly enhanced the levels of PKCß1, RhoA, and RasGFR1 as fruitful molecules in wound healing. These findings provide insights into LMW-sericin application as a potential biomaterial for wound management.

Hemostasis and Anti-Inflammatory Abilities of AuNPs-Coated Chitosan Dressing for Burn Wounds.

Burn injuries are a common hazard in the military, as fire is likely to be weaponized. Thus, it is important to find an effective substance to accelerate burn wound healing. This study used chitosan and gold nanoparticles (AuNPs) as wound dressings and investigated their effectiveness in femoral artery hemorrhage swine and rat burn models. Chitosan dressing has significant hemostatic properties compared with gauze. Histological results showed that burn wounds treated with chitosan or AuNP-coated chitosan dressings exhibited more cells and a continuous structure of the epidermis and dermis than those of the control and untreated lesion groups. Furthermore, both chitosan dressings have been shown to positively regulate the expression of genes- and cytokines/chemokines-related to the wound healing process; AuNP-coated chitosan significantly lessened severe sepsis and inflammation, balanced the activities of pro-fibrotic and anti-fibrotic ligands for tissue homeostasis, regulated angiogenesis, and inhibited apoptosis activity, thereby being beneficial for the burn microenvironment. Hence, chitosan alone or in combination with AuNPs represents a prospective therapeutic substance as a burn dressing which might be helpful for burn wound care. This study provides a novel hemostasis dressing for modern warfare that is simple to use by most medical and paramedical personnel handling for burn treatment.

Germanium-Titanium-π Polymer Composites as Functional Textiles for Clinical Strategy to Evaluate Blood Circulation Improvement and Sexual Satisfaction.

By continuously enhancing the blood flow, far-infrared (FIR) textile is anticipated to be a potential non-pharmacological therapy in patients with peripheral vascular disorders, for instance, patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and experiencing vasculogenic erectile dysfunction (VED). Hence, we manufactured a novel polymer composite, namely, germanium-titanium-π (Ge-Ti-π) textile and aimed to evaluate its characteristics and quality. We also investigated the immediate and long-term effects of the textile on patients with ESRD undergoing HD and experiencing VED. The Ge-Ti-π textile was found to have 0.93 FIR emissivity, 3.05 g/d strength, and 18.98% elongation. The results also showed a 51.6% bacteria reduction and negative fungal growth. On application in patients receiving HD, the Ge-Ti-π textile significantly reduced the limb numbness/pain (p < 0.001) and pain score on the visual analog scale (p < 0.001). Moreover, the Doppler ultrasound assessment data indicated a significant enhancement of blood flow in the right hand after 1 week of Ge-Ti-π textile treatment (p < 0.041). In VED patients, the Ge-Ti-π underpants treatment significantly improved the quality of sexual function and increased the average penile blood flow velocity after 3 months of the treatment. Our study suggests that the Ge-Ti-π textile could be beneficial for patients with blood circulation disorders.

Bacterial Cellulose as a Potential Bio-Scaffold for Effective Re-Epithelialization Therapy.

Currently, there are several therapeutic approaches available for wound injury management. However, a better understanding of the underlying mechanisms of how biomaterials affect cell behavior is needed to develop potential repair strategies. Bacterial cellulose (BC) is a bacteria-produced biopolymer with several advantageous qualities for skin tissue engineering. The aim here was to investigate BC-based scaffold on epithelial regeneration and wound healing by examining its effects on the expression of scavenger receptor-A (SR-A) and underlying macrophage behavior. Full-thickness skin wounds were generated on Sprague-Dawley rats and the healing of these wounds, with and without BC scaffolds, was examined over 14 days using Masson's trichome staining. BC scaffolds displayed excellent in vitro biocompatibility, maintained the stemness function of cells and promoted keratinocyte differentiation of cells, which are vital in maintaining and restoring the injured epidermis. BC scaffolds also exhibited positive in vivo effects on the wound microenvironment, including improved skin extracellular matrix deposition and controlled excessive inflammation by reduction of SR-A expression. Furthermore, BC scaffold significantly enhanced epithelialization by stimulating the balance of M1/M2 macrophage re-programming for beneficial tissue repair relative to that of collagen material. These findings suggest that BC-based materials are promising products for skin injury repair.

Cutaneous Regeneration Mechanism of ß-Sheet Silk Fibroin in a Rat Burn Wound Healing Model.

Therapeutic dressings to enhance burn wound repair and regeneration are required. Silk fibroin (SF), a natural protein, induces cell migration and serves as a biomaterial in various dressings. SF dressings usually contain α-helices and ß-sheets. The former has been confirmed to improve cell proliferation and migration, but the wound healing effect and related mechanisms of ß-sheet SF remain unclear. We investigated the effects of ß-sheet SF in vivo and in vitro. Alcohol-treated α-helix SF transformed into the ß-sheet form, which promoted granulation formation and re-epithelialization when applied as lyophilized SF dressing (LSFD) in a rat burn model. Our in vitro results showed that ß-sheet SF increased human dermal fibroblast (HDF) migration and promoted the expression of extracellular matrix (ECM) proteins (fibronectin and type III collagen), matrix metalloproteinase-12, and the cell adhesion molecule, integrin ß1, in rat granulation tissue and HDFs. This confirms the role of crosstalk between integrin ß1 and ECM proteins in cell migration. In summary, we demonstrated that ß-sheet SF facilitates tissue regeneration by modulating cell adhesion molecules in dermal fibroblasts. LSFD could find clinical application for burn wound regeneration. Moreover, ß-sheet SF could be combined with anti-inflammatory materials, growth factors, or antibiotics to develop novel dressings.

Procoagulant and Antimicrobial Effects of Chitosan in Wound Healing.

Chitosan, a polysaccharide derived from chitin, has excellent wound healing properties, including intrinsic antimicrobial and hemostatic activities. This study investigated the effectiveness of chitosan dressing and compared it with that of regular gauze dressing in controlling clinically surgical bleeding wounds and profiled the community structure of the microbiota affected by these treatments. The dressings were evaluated based on biocompatibility, blood coagulation factors in rat, as well as antimicrobial and procoagulant activities, and the microbial phylogenetic profile in patients with abdominal surgical wounds. The chitosan dressing exhibited a uniformly fibrous morphology with a large surface area and good biocompatibility. Compared to regular gauze dressing, the chitosan dressing accelerated platelet aggregation, indicated by the lower ratio of prothrombin time and activated partial thromboplastin time, and had outstanding blood absorption ability. Adenosine triphosphate assay results revealed that the chitosan dressing inhibited bacterial growth up to 8 d post-surgery. Moreover, 16S rRNA-based sequencing revealed that the chitosan dressing effectively protected the wound from microbial infection and promoted the growth of probiotic microbes, thereby improving skin immunity and promoting wound healing. Our findings suggest that chitosan dressing is an effective antimicrobial and procoagulant and promotes wound repair by providing a suitable environment for beneficial microbiota.

Inflammatory Regulation by TNF-α-Activated Adipose-Derived Stem Cells in the Human Bladder Cancer Microenvironment.

Mesenchymal stem cells (MSCs), such as adipose-derived stem cells (ADSCs), have the most impressive ability to reduce inflammation through paracrine growth factors and cytokines that participate in inflammation. Tumor necrosis factor (TNF)-α bioactivity is a prerequisite in several inflammatory and autoimmune disease models. This study investigated the effects of TNF-α stimulate on ADSCs in the tumor microenvironment. The RNAseq analysis and cytokines assay demonstrated that TNF-α stimulated ADSCs proliferation and pro-inflammatory genes that correlated to leukocytes differentiation were upregulated. We found that upregulation of TLR2 or PTGS2 toward to IRF7 gene-associated with immunomodulatory and antitumor pathway under TNF-α treatment. In TNF-α-treated ADSCs cultured with the bladder cancer (BC) cell medium, the results showed that apoptosis ratio and OCT-4 and TLR2 genes which maintained the self-renewal ability of stem cells were decreased. Furthermore, the cell survival regulation genes including TRAF1, NF-kB, and IRF7 were upregulated in TNF-α-treated ADSCs. Additionally, these genes have not been upregulated in BC cell medium. A parallel study showed that tumor progressing genes were downregulated in TNF-α-treated ADSCs. Hence, the study suggests that TNF-α enhances the immunomodulatory potential of ADSCs during tumorigenesis and provides insight into highly efficacious MSC-based therapeutic options for BC.

A Novel Intravesical Dextrose Injection Improves Lower Urinary Tract Symptoms on Interstitial Cystitis/Bladder Pain Syndrome.

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a painful recurrent condition characterized by the discomfort of the bladder, and current treatment options have limited effectiveness. Prolotherapy is a well-known treatment that involves the injection of non-biologic solutions to reduce pain and/or promote proliferation of soft tissue, and dextrose is the most common injectate. This study investigated the effects of dextrose prolotherapy in a rat model of IC/BPS and patients with IC/BPS. We used cyclophosphamide to induce IC/BPS in rats, and intravesical instillation of 10% dextrose solution was performed. After 1 week, we conducted a urodynamic test, bladder staining, and ECM-related gene expression analysis to examine the treatment's efficacy. We found that dextrose treatment could recover the instability of the bladder, reduce frequent urination, and improve the glycosaminoglycan layer regeneration and the bladder wall thickness along with a significant intense expression of CD44 receptors. Furthermore, we enrolled 29 IC/BPS patients with previous hyaluronic acid/Botox treatment for more than 6 months with remained unchanged condition. In this study, they received intravesical injections of 10% dextrose solution followed by assessments for up to 12 weeks. Patient characteristics and a 3-day voiding diary before treatment were recorded. Patient responses were examined using IC/BPS-related questionnaires. Moreover, expressions of growth factors and cytokines were analyzed. The results demonstrated that dextrose prolotherapy in patients with IC/BPS reduced the frequency of treatment over time, with the mean number of treatments being 3.03 ± 1.52, and significantly reduced the incidence of nocturia and questionnaire scores associated with symptoms. Dextrose prolotherapy significantly enhanced EGF level and, in contrast, reduced the level of HGF, PIGF-1, and VEGF-D after several weeks following treatment. The cytokine analysis showed that the expressions of IL-12p70 and IL-10 were significantly up-regulated after dextrose prolotherapy in IC/BPS patients. The levels of most growth factors and cytokines in IC/BPS patients had no significant difference and showed a similar tendency as time progressed when compared to healthy controls. Overall, the alteration of growth factors and cytokines exhibited safe treatment and potential stimulation of tissue remodeling. In summary, our study demonstrated that dextrose prolotherapy is a promising treatment strategy for IC/BPS disease management.

Polymeric Gelatin Scaffolds Affect Mesenchymal Stem Cell Differentiation and Its Diverse Applications in Tissue Engineering.

Studies using polymeric scaffolds for various biomedical applications, such as tissue engineering, implants and medical substitutes, and drug delivery systems, have attempted to identify suitable material for tissue regeneration. This study aimed to investigate the biocompatibility and effectiveness of a gelatin scaffold seeded with human adipose stem cells (hASCs), including physical characteristics, multilineage differentiation in vitro, and osteogenic potential, in a rat model of a calvarial bone defect and to optimize its design. This functionalized scaffold comprised gelatin-hASCs layers to improve their efficacy in various biomedical applications. The gelatin scaffold exhibited excellent biocompatibility in vitro after two weeks of implantation. Furthermore, the gelatin scaffold supported and specifically regulated the proliferation and osteogenic and chondrogenic differentiation of hASCs, respectively. After 12 weeks of implantation, upon treatment with the gelatin-hASCs scaffold, the calvarial bone harboring the critical defect regenerated better and displayed greater osteogenic potential without any damage to the surrounding tissues compared to the untreated bone defect. These findings suggest that the present gelatin scaffold is a good potential carrier for stem cells in various tissue engineering applications.

A Collagen-Based Scaffold for Promoting Neural Plasticity in a Rat Model of Spinal Cord Injury.

In spinal cord injury (SCI) therapy, glial scarring formed by activated astrocytes is a primary problem that needs to be solved to enhance axonal regeneration. In this study, we developed and used a collagen scaffold for glial scar replacement to create an appropriate environment in an SCI rat model and determined whether neural plasticity can be manipulated using this approach. We used four experimental groups, as follows: SCI-collagen scaffold, SCI control, normal spinal cord-collagen scaffold, and normal control. The collagen scaffold showed excellent in vitro and in vivo biocompatibility. Immunofluorescence staining revealed increased expression of neurofilament and fibronectin and reduced expression of glial fibrillary acidic protein and anti-chondroitin sulfate in the collagen scaffold-treated SCI rats at 1 and 4 weeks post-implantation compared with that in untreated SCI control. This indicates that the collagen scaffold implantation promoted neuronal survival and axonal growth within the injured site and prevented glial scar formation by controlling astrocyte production for their normal functioning. Our study highlights the feasibility of using the collagen scaffold in SCI repair. The collagen scaffold was found to exert beneficial effects on neuronal activity and may help in manipulating synaptic plasticity, implying its great potential for clinical application in SCI.

Development of a Nucleic Acid Lateral Flow Immunoassay for the Detection of Human Polyomavirus BK.

The BK virus (BKV) is an emerging pathogen in immunocompromised individuals and widespread in the human population. Polymerase chain reaction is a simple and highly sensitive method for detecting BKV, but it is time consuming and requires expensive instruments and expert judgment. The lateral flow assay, a rapid, low-cost, minimal-labor, and easy-to-use diagnostic method, was successfully applied for pathogen detection. In this study, we used oligonucleotide probes to develop a simple and rapid sandwich-type lateral flow immunoassay for detecting BKV DNA within 45 minutes. The detection limit for the synthetic single-stranded DNA was 5 nM. The specificity study showed no cross-reactivity with other polyomaviruses, such as JC virus and simian virus 40. For the Escherichia coli containing BKV plasmid cultured samples, the sensitivity was determined to be 107 copies/mL. The approach offers great potential for BKV detection of various target analytes in point-of-care settings.

Human Adipose-Derived Mesenchymal Stem Cells-Incorporated Silk Fibroin as a Potential Bio-Scaffold in Guiding Bone Regeneration.

Recently, stem cell-based bone tissue engineering (BTE) has been recognized as a preferable and clinically significant strategy for bone repair. In this study, a pure 3D silk fibroin (SF) scaffold was fabricated as a BTE material using a lyophilization method. We aimed to investigate the efficacy of the SF scaffold with and without seeded human adipose-derived mesenchymal stem cells (hASCs) in facilitating bone regeneration. The effectiveness of the SF-hASCs scaffold was evaluated based on physical characterization, biocompatibility, osteogenic differentiation in vitro, and bone regeneration in critical rat calvarial defects in vivo. The SF scaffold demonstrated superior biocompatibility and significantly promoted osteogenic differentiation of hASCs in vitro. At six and twelve weeks postimplantation, micro-CT showed no statistical difference in new bone formation amongst all groups. However, histological staining results revealed that the SF-hASCs scaffold exhibited a better bone extracellular matrix deposition in the defect regions compared to other groups. Immunohistochemical staining confirmed this result; expression of osteoblast-related genes (BMP-2, COL1a1, and OCN) with the SF-hASCs scaffold treatment was remarkably positive, indicating their ability to achieve effective bone remodeling. Thus, these findings demonstrate that SF can serve as a potential carrier for stem cells, to be used as an osteoconductive bioscaffold for BTE applications.

Biological Effects of Chitosan-Based Dressing on Hemostasis Mechanism.

There have been numerous recent advances in wound care management. Nevertheless, the assessment of hemostatic dressing is essential to enable surgeons and other physicians and healthcare professionals to make the correct decisions regarding the disposition of severe hemorrhage. Here, we investigated the relative efficacies of chitosan-based and conventional gauze dressings in a rat model of femoral artery hemorrhage and in patients with surgical wounds. Dressing effectiveness was evaluated based on hemostatic profiles, biocompatibility, antimicrobial activity, and blood factor responses in coagulation. Relative to standard gauze dressing, the chitosan fiber (CF) dressing treatment significantly shortened the time to hemostasis in injured rats. Moreover, the CF dressing significantly prolonged partial thromboplastin time, enhanced blood absorption, and reduced antithrombin production without altering the prothrombin ratio. Unlike regular gauze bandages, the CF dressing demonstrated remarkable antibacterial activity. The results of this study indicate the effectiveness of chitosan as a hemostatic dressing and elucidate its underlying mechanism. It is possible that chitosan surgical dressings could serve as first-line intervention in hospital emergency care for uncontrolled hemorrhage.

Evaluation of Chitosan-based Dressings in a Swine Model of Artery-Injury-Related Shock.

Uncontrolled haemorrhage shock is the highest treatment priority for military trauma surgeons. Injuries to the torso area remain the greatest treatment challenge, since external dressings and compression cannot be used here. Bleeding control strategies may thus offer more effective haemostatic management in these cases. Chitosan, a linear polysaccharide derived from chitin, has been considered as an ideal material for bleeding arrest. This study evaluated the potential of chitosan-based dressings relative to commercial gauze to minimise femoral artery haemorrhage in a swine model. Stable haemostasis was achieved in animals treated with chitosan fibre (CF) or chitosan sponge (CS), resulting in stabilisation of mean arterial pressure and a substantially higher survival rate (100% vs. 0% for gauze). Pigs receiving treatment with CF or CS dressings achieved haemostasis within 3.25 ± 1.26 or 2.67 ± 0.58 min, respectively, significantly more rapidly than with commercial gauze (>100 min). Moreover, the survival of animals treated with chitosan-based dressings was dramatically prolonged (>180 min) relative to controls (60.92 ± 0.69 min). In summary, chitosan-based dressings may be suitable first-line treatments for uncontrolled haemorrhage on the battlefield, and require further investigation into their use as alternatives to traditional dressings in prehospital emergency care.

Activities of Ca2+-related ion channels during the formation of kidney stones in an infection-induced urolithiasis rat model.

Bacterial infection has long been recognized to contribute to struvite urinary stone deposition; however, its contribution to the development of chronic kidney stones has not been extensively investigated. In the present study, we hypothesized another possible method of bacteria contributing to the formation of calcium oxalate (CaOx) that accounts for the biggest part of the kidney stone. Bacteria may play important roles by influencing renal Ca2+-related ion channel activities, resulting in chronic inflammation of the kidney along with rapid aggregation of stones. We examined the correlation among infection-promoted CaOx kidney stones and alterations in Ca2+-related ion channels in an animal model with experimentally induced Proteus mirabilis and foreign body infection. After the bladder was infected for 7 days, the data demonstrated that stones were presented and induced severe renal tubular breakage as well as altered levels of monocyte chemoattractant protein-1, cyclooxygenase-2, osteopontin, and transient receptor potential vanilloid member 5 expression, reflecting responses of kidney ion channels. Monocyte chemoattractant protein-1, osteopontin, and transient receptor potential vanilloid member 5 expression was significantly downregulated over time, indicating the chronic inflammation phase of the kidney and accelerated aggregation of CaOx crystals, respectively, whereas cyclooxygenase-2 exhibited no differences. These results indicated that bacterial infection is considerably correlated with an alteration in renal Ca2+-related ion channels and might support specific and targeted Ca2+-related ion channel-based therapeutics for urolithiasis and related inflammatory renal damage.

Bioapplications of Bacterial Cellulose Polymers Conjugated with Resveratrol for Epithelial Defect Regeneration.

Excellent wound dressing is essential for effective wound repair and regeneration. However, natural polymeric skin substitutes often lack mechanical strength and hydrophilicity. One way to overcome this limitation is to use biodegradable polymers with high mechanical strength and low skin-irritation induction in wet environments. Bacterial cellulose (BC) is an attractive polymer for medical applications; unlike synthetic polymers, it is biodegradable and renewable and has a strong affinity for materials containing hydroxyl groups. Therefore, we conjugated it with resveratrol (RSV), which has a 4'-hydroxyl group and exhibits good biocompatibility and no cytotoxicity. We synthesized BC scaffolds with immobilized RSV and characterized the resulting BC/RSV scaffold with scanning electron microscopy and Fourier-transform infrared spectroscopy. We found that RSV was released from the BC in vitro after ~10 min, and immunofluorescence staining showed that BC was highly biocompatible and regenerated epithelia. Additionally, Masson's trichrome staining showed that the scaffolds preserved the normal collagen-bundling pattern and induced re-epithelialization in defective rat epidermis. These results indicated that RSV-conjugated BC created a biocompatible environment for stem cell attachment and growth and promoted epithelial regeneration during wound healing.

Wet-spinning-based Molding Process of Gelatin for Tissue Regeneration.

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the wet spinning method, gelatin fibers are produced by smooth extrusion in a suitable coagulation medium. To increase the functional surface of these gelatin fibers and their ability to mimic the features of tissues, gelatin can be molded into a tube form by referring to this concept. Examined by in vitro and in vivo tests, the gelatin tubes demonstrate a great potential for application in tissue engineering. Acting as a suitable filling gap material, gelatin tubes can be used to substitute the tissue in the damaged area (e.g., in the nervous or cardiovascular system), as well as to promote regeneration by providing a direct replacement of stem cells and neural circuitry. This protocol provides a detailed procedure for creating a biomaterial based on a natural polymer, and its implementation is expected to greatly benefit the development of correlative natural polymers, which help to realize tissue regeneration strategies.