Enhanced Bone Regeneration in Variable-Type Biphasic Ceramic Phosphate Scaffolds Using rhBMP-2

Our aim was to investigate the bone regeneration capacity of powder-type biphasic ceramic scaffold (BCP powder), block-type BCP (BCP block), and collagen-added block-type BCP (BCP collagen) with different concentrations of recombinant human bone morphogenetic protein 2 (rhBMP-2) in an animal model. Four rabbits were assigned to each of the following groups: no graft + rhBMP-2 (0.1/0.2 mg/mL), BCP powder + rhBMP-2 (0.1/0.2 mg/mL), BCP block + rhBMP-2 (0.1/0.2 mg/mL), and BCP collagen + rhBMP-2 (0.1/0.2 mg/mL), i.e., a total of 32 rabbits. Polycarbonate tubes (Φ 7 mm × 5 mm) for supporting scaffolds were fixed into a 7 mm round border. Subsequently, 0.1 mL of rhBMP-2 solutions with different concentrations was injected into the tubes. Both radiological and histomorphometric analyses showed that osteogenesis was not enhanced by increasing the concentration of rhBMP-2 in all groups at both 3 and 6 weeks. Radiological analysis showed that bone formation was higher in the BCP collagen group than in the BCP powder and BCP block groups at both rhBMP-2 concentrations at 3 weeks. rhBMP-2 enhanced bone formation; however, as the concentration increased, bone formation could not be enhanced infinitely. Collagen-added alloplastic graft material may be useful for mediating rapid bone formation in initial stages.

A comparative study of collagen-based dressing versus conventional dressing in chronic ulcers

Background: Collagen is a fibrous structure, proline-rich protein, comprised of three α-chains, plays an important role in each stage of wound healing, attracts fibroblasts and keratinocytes which in turn encourages debridement, angiogenesis and re-epithelializationMethods: This is a prospective cohort study. After obtaining ethical clearance from Institute’s ethical committee, all the patients fulfilling inclusion criteria were enrolled and written consent was obtained from all the patients. Detailed history was enquired and recorded on a predesigned proforma. The ulcer healing, analysed as- Time required for appearance of healthy granulation tissue, 50% reduction in ulcer size, complete healing time, requirement of skin grafting, time required in return to daily activities.Results: A significant decrease in time required for 50 % reduction in wound size with a mean difference of 18.5 in collagen group patients when compared to 37.5 and 33.0 in Normal saline group patients and Povidone iodine group patients. Chi square test was applied to assess the difference in proportions between groups t test was applied to compare the mean between the groups. P<0.05 was considered as statically significant.Conclusions: Healing with collagen particles is early, compared to the conventional dressings with lesser requirement of skin grafting, number of dressings, shorter hospital stay. Dressing changed every 3-4 days. Healing occurs by formation of early granulation tissue and wound contraction.

Hydrolyzed Collagen Supplementation on Lower Body Stiffness in Recreational Triathletes

Background: Myotendinous stiffness is related to the collagen content of the muscle and tendon, and can be estimated during running by changes in vertical stiffness (kvert) and the resulting modifications of the spatiotemporal parameters (on-off ground asymmetry and landing-takeoff asymmetry). Supplementation with amino acids found in collagen, such as proline, glycine, and hydroxyl proline, combined with ascorbic acid, improve collagen synthesis and potentially result in improved mechanical strength and stiffness. Objectives: To determine if hydrolyzed collagen (HC) supplementation increases kvert and improves the spatiotemporal parameters during running in recreational triathletes. Methods: Nine active males (weight; 68.4 ± 5.7 kg, height; 171.8 ± 5.4 cm, age; 32.5 ± 4.1 years; Vo2max; 53.15 ± 2.19 mL/kg/min) were randomly distributed into a collagen group (CollG, n = 5) and a control group (CG, n = 4). Participants were supplemented for 4 weeks with 15g HC (CollG) or 15g placebo (CG; maltodextrin), 3 times per week. One hour after supplementation, the participants of both groups were asked to perform four repetitions of short sprints to further stimulate collagen synthesis. The ground reaction forces were recorded during running at 4.44 m s-1, 5.55 m.s-1, and 6.66 m.s-1 for assessment of kvert and the spatiotemporal step parameters. Results: Both groups increased kvert with speed (4.44 - 6.66 m s-1) from 24.8 ± 2.7 to 53.7 ± 16.5 N/m and from 25.1 to 49.8 N/m in the CollG and CG, respectively (P < 0.0001); however, there were no differences between groups before and after the supplementation period. As a consequence, the spatiotemporal parameters of running were also similar between groups. Conclusions: Four weeks of HC supplementation does not improve the bouncing mechanism of running in recreational triathletes.

Physical and biological performances of a semi-resorbable barrier membrane based on silk fibroin-glycerol-fish collagen material for guided bone regeneration

The fragility of silk fibroin film is a drawback to being used as a barrier membrane. Semi-resorbable barrier membranes maintain function longer than a resorbable membrane and no need to be removed. The study aimed to fabricate semi-resorbable membranes using silk fibroin with glycerol plasticizer (Group A), immobilized with fish collagen (Group B), and then characterized, in vitro biocompatibility tested, and compared with a commercial collagen membrane (Group C). Group B showed more roughness (0.2155 µm) than Group A (0.1424 µm). Group A was more hydrophilic (76.75° ± 3.07°) and more stiffness (28.93% ± 15.56%) than Group B (112.67° ± 1.94°, 42.10% ± 11.46%) and C (54.79% ± 13.44%) without significant difference. Group C had a significantly higher ( p < 0.05) swelling degree and less degradation rate than others. Group A showed significantly highest ( p < 0.05) cell proliferation. Group C showed more alkaline phosphatase activity than others but no significant difference in osteocalcin and Alizarin Red activity on day 21. The semi-resorbable membrane based on silk fibroin-glycerol possessed good physical and mechanical properties, and well-supported osteoblastic cell proliferation and differentiation.

A retrospective study of comparison of collagen dressing versus conventional dressing for skin graft donor site

Background: Split-skin grafting is commonly employed for covering skin defects in case of ulcers, deep burns and following trauma. It involves harvesting of the epidermis and upper 1/3rd of dermis resulting in a wound called donor site wound (DSW). These wounds pose a kind of burden to patients during the process and after the process of wound healing. These wounds tend to cause pain, are at risk of getting infected, pruritis and cosmetic inconvenience. DSW has been managed with closed or open dressings. Out of many methods, we aim to compare the efficacy of collagen dressing with that of conventional dressing in this study.Methods: A retrospective study including 30 subjects were stratified into 2 groups; group A-collagen dressing and group B- conventional dressing. Patients aged between 18 to 60 years undergoing split thickness skin grafting were included. Patients who are immunocompromised, diabetic, with underlying skin disease and infected wounds were excluded. The outcome was compared in terms of pain, pruritis and scar assessment using Vancouver scar scale.Results: In the present study there was significant difference in median pain score, pruritus and median Vancouver scar score in collagen group compared to conventional group at all the intervals. Also, the incidence of surgical site infection was lower in the collagen dressing group.Conclusions: Collagen dressing is superior compared to conventional dressing in terms of lower pain score, pruritus score and Vancouver scar score.

Undenatured type II collagen mitigates inflammation and cartilage degeneration in healthy Labrador Retrievers during an exercise regimen

The aim of this experiment was to evaluate the effect of undenatured type II collagen supplementation on inflammation and cartilage degeneration after exercise in healthy dogs. Forty healthy Labrador Retrievers (20 male/20 female; Range 5-12yrs; Avg 8yrs) were sorted into two groups: undenatured type II collagen group receiving 40mg UC-II (10mg Collagen Type II/Min. 3% Undenatured Type II Collagen; Lonza Consumer Health, Inc.) and placebo group receiving 40mg maltodextrin daily by capsule. After 2-weeks loading, all dogs began an 11-week endurance exercise regimen consisting of two weekly runs, starting at 5km and increasing incrementally to 8km, with one final 16km run. Blood samples were collected at baseline, pre and post first 5km run, and pre and post 16km run. Activity per kilometer was greater in male undenatured type II collagen vs male placebo over all runs (P=0.004), and average moving speed was greater in all undenatured type II collagen dogs compared with placebo over all runs (P&lt;0.001). Hematology analysis indicated that during the first insult, undenatured type II collagen dogs had a greater lymphocyte count (P&lt;0.001) and lymphocyte percentage (P=0.001) vs placebo dogs. Undenatured type II collagen dogs had a lesser neutrophil percentage (P=0.042) and neutrophil to lymphocyte ratios (P=0.001) compared to placebo dogs. For the final insult, undenatured type II collagen dogs had greater lymphocyte percentage (P=0.013) and lesser mean corpuscular hemoglobin concentration (P=0.043) compared with placebo dogs. Both groups had significant changes between timepoints for several hematological parameters. Biomarker IL-6 was lesser in undenatured type II collagen dogs compared with placebo at post 5km (P=0.037). Cartilage oligomeric matrix protein (COMP) was lesser in undenatured type II collagen dogs at post 16km (P=0.023), and only the placebo dogs had a significant increase in COMP from pre to post 16km (P=0.021). In summary, Labrador Retrievers supplemented with undenatured type II collagen had decreased inflammation and cartilage degeneration compared with non-supplemented dogs during exercise.

LOCAL APPLICATION OF GROWTH HORMONE INDUCES INCREASED IMMUNOEXPRESSION OF IGF-I ON CRANIOFACIAL BONE DEFECTS REPAIR – A PILOT STUDY

The aim is to evaluate the local effect of different concentrations of growth hormone (GH) on the repair of craniofacial bone defects, through histological, histomorfometric, and insulin-like growth factor I (IGF-I) immunoexpression assessments. Critical defects (5 mm) were performed in 32 Wistar rats. The animals were divided into four groups: Group C (Control); Group S (Sponge-collagen); Group GH 0.08 mL; GH 0.104 mg; Group GH 0.1mL. Local applications were performed 3 times a week until the rats were euthanized at 60 days. The data were submitted to ANOVA and Tukey's test (P < 0.05). A healing process with predominance of collagen bers and bone neoformation near the edges of the defect was observed in groups C and S. Islands of bone neoformation were observed at the center and edges of the defect in groups GH 0.08 and GH 0.1. In GH 0.1, the bone was more compact, and the defect was completely closed in some specimens. Bone neoformation was signicantly higher in the GH-treated groups. All the specimens stained positive for IGF-I, and this immunoexpression was signicantly higher in Group GH 0.1. In conclusion, locally applied GH signicantly favored bone repair in rat calvaria, and a higher dose of GH increased the immunoexpression of IGF-I.

COLLAGEN DRESSING VERSUS CONVENTIONAL DRESSINGS IN BURN AND CHRONIC WOUNDS: A COMPARATIVE STUDY

Objective: Biological dressings are water-resistant to bacteria, and generate the most physiological interfacebetween the wound surface and the environment. Collagen dressings have other superiority over conventional dressings in terms of ease of application and being natural, non-immunogenic, non-pyrogenic, hypoallergenic, and pain-free. Materials And Methods: The data of 120 patients with chronic wounds of diverse aetiologies and with signify age 43.7 years were accumulated and analyzed. The patients had been treated with collagen or other conventional dressing substance. The patients were split into two groups; 'Collagen group' and 'Conventional group', For the cause of comparison. 60 patients wereincluded in both groups. For assessment the wound characteristics in size, edge, oor, granulation tissue, and wound swab were recorded. With starting treatment, appearance of granulation tissue, completeness of healing, require for skin grafting, and patients' satisfaction was noted in both groups. Results: Sixty percentage of the 'collagen group' wounds and only forty-two percentage of the 'conventionalgroup' wounds were sterile (P=0.04) within two weeks of treatment. Healthy granulation tissue seemed earlier over collagen-dressed woundsthan over conventionally treated wounds (P=0.04). After eight weeks, (87%) of 'collagen group' wounds and (80%) of 'conventional group' wounds were >75% healed (P=0.21). In the 'collagen group' eight patients and twelvein the 'conventional group' required partial split-skin grafting (P=0.05). Collagen-treated patients enjoyed early. Conclusion: No remarkable better results were found in terms of complete of healing of burn andchronic wounds between collagen dressing and conventional dressing. Collagen dressing, however, mayavoid the require of skin grafting, and provides additional benet of patients' comfort.

Evaluation of Guided Bone Regeneration in Critical Defects Using Bovine and Porcine Collagen Membranes: Histomorphometric and Immunohistochemical Analyses

Guided bone regeneration (GBR) is a technique used to facilitate bone regeneration, which uses a biocompatible membrane acting as a physical barrier to prevent the adjacent connective tissue from invading the bone defect. The aim of this study was to evaluate and compare the effectiveness of bovine and porcine collagenous membranes as barriers to connective tissue invasion during the repair of critical bone defects in rat calvaria, using histological, histometric, and immunohistochemical analyses. For this study, 72 rats were divided into three groups: clot group (CG), bovine collagen group (BCG), and porcine collagen group (PCG). Analyses were performed on days 7, 15, 30, and 60. The histological results showed that the PCG exhibited bone neoformation starting from day 7, and after 30 days of repair, the surgical defect was completely filled in some animals. For the BCG, there was little bone neoformation activity in the initial periods, and from day 30 onwards, there was an increase in bone neoformation, with a greater increase on day 60. The data obtained in the histometric analysis reveal that, on day 30, the neoformed bone area did not vary greatly between the PCG and the BCG, though both varied from the CG. By day 60, the PCG presented a greater area of neoformation than the BCG. These results were corroborated by the immunohistochemistry results. In view of the results obtained, it can be concluded that all membranes studied in this research promoted GBR.

Rat Bone Marrow Derived Mesenchymal Stem Cells (rBMMSCs) Encapsulated in Collagen Type I Containing Platelet-Rich Plasma for Osteoarthritis Treatment in Rat model

Osteoarthritis (OA) is the most common form of degenerative joint disease, affecting more than 25% of the adult though prevalent in the elderly population. Most of the current therapeutic modalities aim at symptomatic treatment and lingering the disease progression. In recent years, regenerative medicine such as stem cell transplantation and tissue engineering has been suggested as a potential curative intervention for OA. The objective of current study was to assess the safety and efficacy of an injectable tissue-engineered construct composed of BMMSCs, PRP, and Collagen type I in rat model of OA. To produce collagen type I, PRP and BMMSCs, male Wistar rats were ethically euthanized. After expansion and characterization of rat BMMSCs (rBMMSCs), tissue-engineered construct was formed by combination of appropriate amount of collagen type I, PRP and rBMMSCs. In vitro studies were conducted to evaluate the effect of PRP on chondrogenic differentiation capacity of encapsulated cells. Then tissue-engineered construct was injected in knee joint of rat model of OA (24 rat in 4 groups: OA, OA+MSC, ‎OA+Collagen+MSC+PRP, OA+MSC+Collagen). After 6 weeks, the animals were euthanized and knee joint histopathology examinations were performed to evaluate the effect of each treatment on OA. Tissue-engineered construct was successfully manufactured and in vitro assays demonstrated that relevant chondrogenic genes and proteins expression were higher in PRP group than the others. Histopathological findings of the knee joint samples showed favorable regenerative effect of rBMMSCs+PRP+Collagen group comparing to others. In this study, we introduced an injectable tissue-engineered product composed of rBMMSCs+PRP+Collagen with potential regenerative effect on cartilage damage caused by OA.