Journal of biomedical materials research. Part B, Applied biomaterials最新文献

The formation of fibrocartilage in microfracture (MFX) severely limits its long-term outlook. There is consensus in the scientific community that the placement of an appropriate scaffold in the MFX defect site can promote hyaline cartilage formation and improve therapeutic benefit. Accordingly, in this work, a novel natural biomaterial—the cartilage analog (CA)—which met criteria favorable for chondrogenesis, was evaluated in vitro to determine its candidacy as a potential MFX scaffold. Human bone marrow stem cells (hBMSCs) were seeded onto the CA and cultured for 28 days in chondrogenic differentiation media. Sulfated glycosaminoglycan (sGAG) and hydroxyproline (HYP) contents were significantly higher than their non-seeded counterparts on both Days 14 and 28 (average sGAG on Day 28: 73.26 vs. 23.82 μg/mg dry wt. of tissue; average HYP on Day 28: 56.19 vs. 38.80 ± 2.53 μg/mg dry wt. of tissue). Histological assessments showed cellular infiltration and abundant sGAG formation for seeded CAs at both time points with new cartilage-like matrix filling up its laser-drilled channels. Polarized light microscopy of picrosirius red stained samples showed collagen fibrils aligning along the path of the laser-drilled channels. However, the seeded scaffolds were also found to have contracted by 20% by the end of the study with their average aggregate moduli significantly lower than non-seeded controls (10.52 vs. 21.74 kPa). Nevertheless, the CA was ultimately found to support the formation of a cartilage-like matrix, and therefore, merits consideration as a scaffold of interest for improving MFX.

Burns are complex traumatic injuries that lead to severe physical and psychological problems due to the prolonged healing period and resulting physical scars. Owing to their versatility, hydrogels can be loaded with various functional factors, making them promising wound dressings. However, many hydrogel dressings cannot support cell survival for a long time, thereby delaying the process of tissue repair. Herein, based on chitosan (CS)/alginate (SA)/poly(ethylene glycol) diacrylate (PEGDA), a basic hydrogel with hemostasis and antibacterial properties was prepared, and loaded with vascular endothelial cadherin (VE-cadherin) and fibroblast growth factors (FGF) to promote the co-culture of various skin cells, suitable for treating various skin injury types: (1) Construct a three-dimensional microenvironment conducive to the release of drugs and factors using natural biological macromolecules CS/SA. (2) Promote the cell growth by loading growth factors. (3) Establish skin burn models of different degrees and observe the repair process. From the results, the 3D microenvironment provided by hydrogel could support the active growth of cells for 12 days. Furthermore, deep burns with full-thickness skin were substantially repaired within about 24 days. Collectively, CS/SA hydrogel containing VE-cadherin and FGF can promote tissue healing in wounds with necrotic tissue, making it an ideal candidate for burn treatment.

Massive bleeding and bacterial infection of wounds may be life-threatening or even lead to death. Nowadays, gelatin-based hemostatic sponges have been widely used, but gelatin is not antibacterial and has poor structural stability. In this study, we mixed an antibacterial polypeptide, ε-poly-L-lysine (EPL), into gelatin. A gelatin/ε-poly-L-lysine (Gel/EPL) sponge with hemostatic and antibacterial functions was prepared by ultraviolet (UV) crosslinking lyophilized Gel/EPL composite. Scanning electron microscopy showed that the sponge had an interconnected porous structure. The incorporation of EPL increased the hydrophilicity and water absorption capacity of the Gel/EPL sponge. The sponge had better structural stability after UV crosslinking. The antibacterial assay showed that bacteria could not grow normally around the Gel/EPL sponge. The contact between blood components and the sponge initiated coagulation via exogenous pathway activation, and no hemolysis occurred. In addition, in vivo experiments confirmed that the sponge has a faster clotting time and lower blood loss. These findings show that the developed Gel/EPL sponge has great potential as a novel hemostatic agent that can quickly stop bleeding and fight bacterial infections.

The purpose of this study was to evaluate the characteristics of the ceramic bonding to cobalt–chromium (Co–Cr) alloys fabricated by casting, milling, and additive manufacturing, compared with zirconia and nickel–chromium. One hundred specimens (N = 100), prepared with the dimensions of 25 × 3 × 0.5 mm³, were assigned to five groups (n = 20): presintered milled Co–Cr (Group M), additively manufactured Co–Cr (Group SLM), cast Co–Cr (Group C), presintered zirconia (Group Zi), and cast Ni–Cr (Group Ni). The bar specimens were prepared to receive porcelain on their central area (8 × 3 mm²) of one side of each alloy strip. Only half of the specimens from each group were exposed to thermocycling (5°C–55°C for 5000 times). All specimens were placed in a bending device. Specimen surface morphology was examined by scanning electron microscopy. The bonding values between materials and the aging treatment effect groups were compared with two-way ANOVA. Variances were compared using the Levene test, the Bonferroni adjustment was used for multiple pairwise comparisons. The shape (m) and scale (σ₀) parameters of the two-parameter Weibull distribution values were calculated. Thermocycling did not affect the results of all the groups tested (p = 0.237). Statistical difference was found between the Co–Cr groups, and between groups Ni and Zi when compared to groups C and SLM (p < 0.001). Ni had the lowest adhesion values and cast Co–Cr the highest. A statistical difference was found between the three Co–Cr groups (p < 0.001), with the highest ceramic adhesion found in Group C and the lowest found in Group M. All specimens from Groups M, C, and Ni showed adhesive failures, whereas mixed failures were observed in Groups Zi and SLM. The fit of the maximum-likelihood line was a poor fit in the distribution of the aged SLM group (p < 0.010). Ceramic adhesion and failure types varied with the alloy choice and the manufacturing technique.

A new method is developed using elastic lipid nanovesicles (ELNs) loaded with ethanolic extract of Lantana camara (LC) to enhance skin permeation of plant actives. The ELNs contained cholesterol, 1, 2-distearoyl-sn-glycero-3-phosphocholine, span 80, and tween 80. Firstly, 15 formulations were produced to examine critical factors likely affecting formulation characteristics. In addition, surface characteristics, vesicle size, polydispersity index, zeta potential, degree of deformability, and % entrapment efficiency (% EE) of ELN were examined. As a significant parameter, skin permeation was measured (using Start-M; it highly resembles human skin). The influence of size, hydrophilic–lipophilic balance (HLB), and surface ratio were vital to permeation through Start-M. In particular, the % LC extract permeation decreased at more extensive size ranges, 400, and 350–450 nm. In contrast, the % LC extract permeation increased significantly at smaller size ranges, such as 200 and 100 nm. More than 75% of the LC extract was permeated within 8 h when the surfactant ratio was (span 80:tween 80; 25%:75%). Permeation studies conducted based on HLB values revealed that 78% of LC extract was permeated in 8 h when HLB was 12.2, and that permeation decreased with an increase in HLB. Cell viability assay using SK-MEL-37 cells (skin cancer) revealed that ELN reduced the viability by ~80% in 24 h, further validating the formulation. Future research could investigate the long-term safety and therapeutic potential of these ELNs in clinical settings and their effectiveness in delivering other plant-based extracts for transdermal applications via ELNs.

Addressing the high cost and long cycle associated with the multistep digital restoration process involving 3D printing technology, we proposed the 3D pen as an innovative strategy for rapid bone repair. Capitalizing on the low melting point characteristic of polycaprolactone (PCL), we introduced, for the first time, the novel concept of directly constructing scaffolds at bone defect sites using 3D pens. In this in vitro study, we meticulously evaluated both the mechanical and biological properties of 3D pen-printed PCL scaffolds with six distinct textures: unidirectional (UNI) (0°, 45°, 90°), bidirectional (BID) (−45°/45°, 0°/90°), and concentric (CON). The bone repair scaffold creation process was simulated using a fused deposition modeling (FDM) 3D printer and a 3D pen by creating a cattle bone defect model to compare the achieved scaffold time efficiency and accuracy. Mechanical test results revealed that 3D pen-printed scaffolds with different textures exhibited varying results in four tests, except the shear bond test. Optimal scaffold strength was consistently achieved when printing parallel to the applied force. Regarding biological properties, these scaffolds exhibited consistent cell viability over time and showcased excellent cell attachment capabilities overall. Furthermore, cells grew regularly along the printed filaments, with additional living cells at high elevations observed. Additionally, the 3D pen method outperformed traditional digital technology with an FDM 3D printer concerning accuracy and speed. These findings underscored the tremendous potential of the 3D pen in the realm of medical science, specifically within the domain of bone tissue engineering, characterized by its low cost, high speed, and convenience.

Despite the variety of proposed solutions, anastomotic leakage is still a critical complication after colorectal surgery, which causes increased clinical mortality and morbidity. By enhancing microcirculation in the colonic mucosa, the use of Iloprost (Ilo) has shown promising results for the healing of anastomosis. The purpose of this study is to examine the performance of Ilo-impregnated Polycaprolactone:Gelatin electrospun membranes (PCL/Gel/Ilo) on anastomosis repair and intra-abdominal adhesion behavior in the Rat colon. Wistar Albino rats were randomly divided into four groups: sham, Control (only resection-anastomosis), PCL/Gel, and PCL/Gel /Ilo (n = 12 for each). On the seventh day after colon anastomosis, a second laparotomy was conducted. During this procedure, intra-abdominal adhesion was examined, and the anastomotic segment was removed for burst pressure and histological evaluation. There was no statistically significant difference in intra-abdominal adhesions and major complications between the electrospun membrane groups and the control group. The membrane-applied groups exhibited significantly higher anastomotic burst pressure than the control group irrespective of their Ilo content. In terms of neovascularization and muscle necrosis, membrane-applied groups demonstrated statistically significant improvements over the control group. Furthermore, the PCL/Gel/Ilo applied group showed enhanced neovascularization and lower muscular necrosis; however, statistically significant differences were not observed compared to the PCL/Gel applied group. Compared to the control group, the application of electrospun PCL/Gel and PCL/Gel/Ilo membranes resulted in safe and effective healing of colon anastomosis. The fact that Ilo application cannot be distinguished from the regular membrane group necessitates additional research into the doped fibrous mat and its application method.

IntroductionProlonged hyperglycemia in diabetic patients often impairs wound healing, leading to chronic infections and complications. This study aimed to evaluate the potential of fresh Tilapia fish skin as a treatment to enhance wound healing in diabetic rats. MethodsThirty-nine healthy adult albino rats, weighing between 150 and 200 g, were divided into three groups: non-diabetic rats with untreated wounds [C-], diabetic rats with untreated wounds [C+], and diabetic rats treated with fresh Tilapia skin [TT]. The healing process was monitored through clinical observation, gross examination, and histopathological analysis. ResultsThe results demonstrated that the Tilapia skin treatment accelerated wound healing, as evidenced by complete reepithelialization, full epidermal cell differentiation, an intact dermo-epidermal junction, and a reorganized dermis with fewer blood vessels. ConclusionFresh Tilapia skin proved to be a safe and effective dressing for promoting wound healing and managing infection in diabetic wounds.