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Repair of bone defects can be done using tissue engineering involving a combination of scaffold, stem cells, and growth factors. The natural scaffold that is commonly used is Deproteinized Bovine Bone Material (DBBM), but it is only osteoconductive and not osteoinductive and has slow biodegradation. Another alternative to the scaffold is Freeze Dried Bovine Bone (FDBB) which has better osteoconductive properties and decellularization scaffold called decellularization Freeze-Dried Bovine Bone (dc-FDBB). In the tissue engineering process, scaffold can induce the differentiation of mesenchymal stem cells and osteoprogenitor cells into osteoblasts which then form the bone matrix. The process of osteoblast formation will affect the increase in Collagen type 1 (COL-1) and Alkaline Phosphatase (ALP) genes. The bjective to compare the expression of COL-1 and ALP on FDBB and DBBM scaffolds for bone tissue engineering. The study was an in vitro laboratory experiment on human Umbilical Cord Mesenchymal Stem Cells (hUC-MSC). There were five treatment groups, group 1 immersion of hUC-MSC on basic medium, group 2 immersion of hUCMSC on osteogenic medium, group 3 FDBB on osteogenic medium, group 4 decellularized dcFDBB on osteogenic medium, and group 5 DBBM on osteogenic medium. Furthermore, RT-PCR readings were carried out on the sixth and 12th days, with each sample replicated two times. Data analysis was carried out using the one-way Analysis of Variance (ANOVA) test. As a result Group 1 showed the highest mean of ALP and COL-1 expression compared to other groups on day six and day 12. One-way ANOVA analysis test showed p<0.05 which indicated a significant difference between groups in the expression of ALP and COL-1. In conclusion the FDBB scaffold showed the highest ALP and COL-1 expression when compared to the DBBM and dc-FDBB groups. [ABSTRACT FROM AUTHOR]

Compared to pure hyaluronic acid filler, cross-linked hyaluronic acid (HAc) exhibits superior biocompatibility and longevity as a dermal filler. We previously developed composite HAc-hydroxyapatite (HAp) fillers. Herein, we systematically compared the protein-level increase and gene expression between HAc-micro-HAp and HAc-nano-HAp in mice and determined the mechanisms underlying the biological responses to HAc and HAp. Five-week-old female BALB/c-nude mice were classified into five groups: normal skin, Radiesse, Restylane, HAc-nano-HAp, and HAc-micro-HAp. Fillers (200 μl) were injected to evenly fill the back of mice. Skin biopsies were performed to investigate collagen and elastic fiber synthesis after filler injections. Western blot analysis, real-time polymerase chain reaction analysis, and immunohistochemistry were performed to investigate protein and gene expression changes. Organ (liver, lung, spleen, and kidney) toxicity of HAc-nano-HAp was determined by hematoxylin and eosin staining after 12 weeks. Protein and gene expression analyses indicated that, compared with pure fillers, HAc-nano-HAp and HAc-micro-HAp hydrogels preferentially promoted collagen and elastic fiber formation through the TGF-β pathway. The composite fillers also exhibited no evidence of organ toxicity. HAc–HAp filler might play an important role in collagen and elastic fiber regeneration. HAc filler stimulates collagen type 1 and elastic fiber synthesis through the TGF-β/Smad pathway. The role of HAc–HAp composite fillers in photoaging in animal models and their effects on skin, including elasticity and tensile strength, should be investigated. [ABSTRACT FROM AUTHOR]

The design of constructs for tubular tissue engineering is challenging. Most biomaterials need to be reinforced with supporting structures such as knittings, meshes or electrospun material to comply with the mechanical demands of native tissues. In this study, coupled helical coils (CHCs) were manufactured to mimic collagen fiber orientation as found in nature. Monofilaments of different commercially available biodegradable polymers were wound and subsequently fused, resulting in right-handed and left-handed polymer helices fused together in joints where the filaments cross. CHCs of different polymer composition were tested to determine the tensile strength, strain recovery, hysteresis, compressive strength and degradation of CHCs of different composition. Subsequently, seamless and stable hybrid constructs consisting of PDSII® USP 2-0 CHCs embedded in porous collagen type I were produced. Compared to collagen alone, this hybrid showed superior strain recovery (93.5 ± 0.9% vs 71.1 ± 12.6% in longitudinal direction; 87.1 ± 6.6% vs 57.2 ± 4.6% in circumferential direction) and hysteresis (18.9 ± 2.7% vs 51.1 ± 12.0% in longitudinal direction; 11.5 ± 4.6% vs 46.3 ± 6.3% in circumferential direction). Furthermore, this hybrid construct showed an improved Young’s modulus in both longitudinal (0.5 ± 0.1 MPa vs 0.2 ± 0.1 MPa; 2.5-fold) and circumferential (1.65 ± 0.07 MPa vs (2.9 ± 0.3) × 10 −2 MPa; 57-fold) direction, respectively, compared to templates created from collagen alone. Moreover, hybrid template characteristics could be modified by changing the CHC composition and CHCs were produced showing a mechanical behavior similar to the native ureter. CHC-enforced templates, which are easily tunable to meet different demands may be promising for tubular tissue engineering. Statement of Significance Most tubular constructs lack sufficient strength and tunability to comply with the mechanical demands of native tissues. Therefore, we embedded coupled helical coils (CHCs) produced from biodegradable polymers – to mimic collagen fiber orientation as found in nature – in collagen type I sponges. We show that the mechanical behavior of CHCs is very similar to native tissue and strengths structurally weak tubular constructs. The production procedure is relatively easy, reproducible and mechanical features can be controlled to meet different mechanical demands. This is promising in template manufacture, hence offering new opportunities in tissue engineering of tubular organs and preventing graft failure. [ABSTRACT FROM AUTHOR]

Purpose: The goal from this in vitro study was to evaluate osteoblast protein expression of collagen type 1 (col 1) and osteopontin (OPN) on titanium surface treated with double etching compared with a zirconia implant surface. Materials and Methods: Discs were selected on both surfaces with respective treatments. Mouse MC3T3-E1 osteoblastic cells were tested for cell viability using the MTT assay. Subsequently, the quantification of col 1 and OPN secreted by osteoblastic cells plated on different surfaces was evaluated by enzyme linked immunosorbent assay (ELISA). Results: Regarding the cell proliferation, statistical analysis showed no significant effect of surface-time interaction and viable cell count on the surfaces of titanium versus zirconia. No statistical differences between the surfaces of titanium and zirconia on cell viability was found. The zirconia surface expression of OPN was significantly higher, which occurred in all times. Furthermore, zirconia demonstrated significantly greater in col 1 expression in 48 and 96 hours compared with titanium. Conclusion: In this study, the zirconia surface demonstrated OPN and col 1 expression significantly higher as compared with titanium. [ABSTRACT FROM AUTHOR]

Purpose A readily available artificial urinary conduit might be substituted for autologous bowel in standard urinary diversions and minimize bowel associated complications. However, the use of large constructs remains challenging as host cellular ingrowth and/or vascularization is limited. We investigated large, reinforced, collagen based tubular constructs in a urinary diversion porcine model and compared subcutaneously pre-implanted constructs to cell seeded and basic constructs. Materials and Methods Reinforced tubular constructs were prepared from type I collagen and biodegradable Vicryl® meshes through standard freezing, lyophilization and cross-linking techniques. Artificial urinary conduits were created in 17 female Landrace pigs, including 7 with a basic untreated construct, 5 with a construct seeded with autologous urothelial and smooth muscle cells, and 5 with a free graft formed by subcutaneous pre-implantation of a basic construct. All pigs were evaluated after 1 month. Results The survival rate was 94%. At evaluation 1 basic and 1 cell seeded conduit were occluded. Urinary flow was maintained in all conduits created with pre-implanted constructs. Pre-implantation of the basic construct resulted in a vascularized tissue tube, which could be used as a free graft to create an artificial conduit. The outcome was favorable compared to that of the other conduits. Urinary drainage was better, hydroureteronephrosis was limited and tissue regeneration was improved. Conclusions Subcutaneous pre-implantation of a basic reinforced tubular construct resulted in a vascularized autologous tube, which may potentially replace bowel in standard urinary diversions. To our knowledge we introduce a straightforward 2-step procedure to create artificial urinary conduits in a large animal model. [ABSTRACT FROM AUTHOR]

Background: The purpose of this experimental study was to evaluate the collagen fiber distribution histologically after phenytoin, cyclosporin, or nifedipine therapy and to correlate it with collagen 1 and matrix metalloproteinase (MMP)-1 and -2 gene expression levels. Methods: Gingival samples from the canine area were obtained from 12 male monkeys (Cebus apella). The mesial part of each sample was assessed by reverse transcription-polymerase chain reaction, whereas the distal part was processed histologically for picrosirius red and hematoxylin and eosin stainings, as well as for collagen IV immunostaining. One week after the first biopsy, the animals were assigned to three groups that received daily oral dosages of cyclosporin, phenytoin, or nifedipine for 120 days. Additional gingival samples were obtained on days 52 and 120 of treatment from two animals from each group on the opposite sides from the first biopsies. Results: Picrosirius red staining showed a predominance of mature collagen fibers in the control group. Conversely, there was an enlargement of areas occupied by immature collagen fibers in all groups at days 52 and 120, which was not uniform over each section. There was a general trend to lower levels of MMP-1 gene expression on day 52 and increased levels on day 120. Phenytoin led to increased levels of MMP-2 and collagen I gene expression on day 120, whereas the opposite was observed in the nifedipine group. Conclusion: Cyclosporin, phenytoin, and nifedipine led to phased and drug-related gene expression patterns, resulting in impaired collagen metabolism, despite the lack of prominent clinical signs. [ABSTRACT FROM AUTHOR]

The Ets-1 oncoprotein and the heme-catabolizing enzyme heme oxygenase (HO)-1 have been implicated in the pathogenesis of renal disease. We investigated the role of the putative Ets-binding sites (EBSs) in the transactivation of the proximal promoter of rat heme oxygenase 1 (hmox1) gene by the Ets oncoproteins Fli-1, Erg-2, and Ets-1 in mesangial cells. We examined several rat hmox1-chloramphenicol acetytransferase (CAT) constructs and EBS mutant constructs in an effort to assess the effect of ETS oncoproteins on transactivation of the rat hmox1 proximal promoter in renal glomerular mesangial cells. CAT assays demonstrated that the proximal promoter region (−1387 to −40) contains positive and negative regulatory regions and that the EBS-2, 3, and 4 play a role in basal promoter activity. Overexpression of Fli-1 and Erg-2 proteins showed a significant increase in promoter activity, whereas Ets-1 showed no effect on promoter activity. The Fli-1–induced transcriptional activation was not altered by mutation of EBSs, either independently or in combination. However, mutation of EBS-4 independently or a combined mutation of sites 3 and 4 led to a 50% reduction in Erg-2–induced transcriptional activation. Furthermore, mutation of EBS-2 and 4 completely abolished Erg-2–mediated promoter activation. Our results support a role for Ets transcription factors in the regulation of rat hmox-1 gene expression in mesangial cells. [Copyright &y& Elsevier]