Tissue Tensile Strength Research Articles

Pericardium decellularization in a one-day, two-step protocol.

Scaffolds used in tissue engineering can be obtained from synthetic or natural materials, always focusing the effort on mimicking the extracellular matrix of human native tissue. In this study, a decellularization process is used to obtain an acellular, biocompatible non-cytotoxic human pericardium graft as a bio-substitute. An enzymatic and hypertonic method was used to decellularize the pericardium. Histological analyses were performed to determine the absence of cells and ensure the integrity of the extracellular matrix (ECM). In order to measure the effect of the decellularization process on the tissue's biological and mechanical properties, residual genetic content and ECM biomolecules (collagen, elastin, and glycosaminoglycan) were quantified and the tissue's tensile strength was tested. Preservation of the biomolecules, a residual genetic content below 50ng/mg dry tissue, and maintenance of the histological structure provided evidence for the efficacy of the decellularization process, while preserving the ECM. Moreover, the acellular tissue retains its mechanical properties, as shown by the biomechanical tests. Our group has shown that the acellular pericardial matrix obtained through the super-fast decellularization protocol developed recently retains the desired biomechanical and structural properties, suggesting that it is suitable for a broad range of clinical indications.

Three-dimensional structural characterization and mechanical properties of bamboo parenchyma tissue

Bamboo is predominantly composed of parenchyma and fibers, with parenchyma constituting approximately 52% of the bamboo culm wall. The bamboo fibers function as the primary load-bearing elements, its structure and performance have been studied in detail. However, investigations concerning the structure and mechanical properties of parenchyma tissue remain limited. Consequently, this study focuses on the comprehensive characterization of the three-dimensional (3D) structure of bamboo parenchyma. Additionally, the study encompasses the evaluation of tensile and compressive properties of parenchyma tissue, along with an analysis and discourse on failure mechanisms. Parenchyma cells can be categorized into two types: long cells, accounting for approximately 89.37%, and short cells. The measured tensile strength and elastic modulus of the parenchyma tissue are 48.81 MPa and 706.48 MPa, respectively. The propagation of cracks leading to tensile failure predominantly occurs along the middle lamella, accompanied by partial penetration through cell walls. Concerning parenchyma tissue compression, three discernible stages can be identified: the elastic stage, plateau stage, and densification stage. The axial load-bearing capacity of parenchyma tissue exceeds that of the tangential and radial orientations. Axial compressive strength and elastic modulus of the parenchyma are measured at 18.82 MPa and 5.24 GPa, respectively. Compression failure modes in parenchyma tissue encompass compression bending and cell fracture, shear failure of the middle lamella, and detachment and debonding of the cell wall. The comprehensive structural and mechanical parameters derived from this investigation provide valuable insights for the development of numerical models and understanding the various mechanical properties of bamboo.

Polydopamine modified cellulose nanocrystals (CNC) for efficient cellulase immobilization towards advanced bamboo fiber flexibility and tissue softness

Herein, a green facile approach to improve the flexibility of unbleached bamboo kraft pulp (UBKP) via an immobilized enzyme technology is proposed. Polydopamine (PDA) acts as versatile modification and coating materials of cellulose nanocrystals (CNC) for assembling versatile bio-carriers (PDA@CNC). Cellulase biomacromolecules are efficiently immobilized on PDA@CNC to form cellulase@PDA@CNC nanocomposites. The relative enzyme activity, temperature/pH tolerance, and storage stability of cellulase were significantly improved after immobilization. The degree of polymerization treated UBKP decreased by 5.42 % (25 U/g pulp) compared to the control sample. The flexibility of treated fibers was 6.61 × 1014/(N·m2), which was 96.93 % higher (25 U/g) compared to the control and 3.88 times higher than that of the blank fibers. Cellulase@PDA@CNC performs excellent accessibility to fiber structure and induces high degree of fibrillation and hydrolysis of UBKP fibers, which contributes high softness of obtained tissue handsheets. The bio-carrier PDA@CNC within paper framework may further enhance tissue tensile strength. This study proposes a practical and environmentally friendly immobilization approach of cellulase@PDA@CNC for improving the hydrolysis efficiency and flexibility of UBKP fibers, which provides the possibility to maintain the strength of tissue paper while improving its softness, thus broadening the high-value application of immobilized enzyme technology in tissue production.

Microstructural and micromechanical modeling of gum-gelatin-based soft tissue engineering scaffolds

Oral and dental diseases, including periodontal disease, are among the most common conditions in the field of dentistry. The best treatment for this complication is the use of different polymers and multi-component biological tissue prepared through the freeze-drying technique. In this study, biocompatible and biodegradable polymers, namely polyvinyl alcohol (PVA) and gelatin (GN), were used for this purpose, along with Arabian gum-hydroxyapatite (HA) for its antibacterial properties. Arabian gum, with weight percentages of 0, 2, 4, and 6 wt%, was added to the polyvinyl alcohol-gelatin composition at −55 °C for 28 h in the freezer and 48 h at −45 °C under a pressure of 0.01 mbar. The resulting porous biological tissue, with four different ratios, was tested for mechanical and biological analysis in a physiological solution. Then, the samples were analyzed using a scanning electron microscope (SEM) and X-ray diffraction (XRD) technique to study the morphology and structure of the compounds before and after placement in biological solutions. Additionally, a wettability and antibacterial test were performed on the nanocomposite specimen. The SEM observations reveal that this method can create a porous structure with a porosity of about 30–50 μm with a spherical and circular architecture, which was further improved by the addition of gum, reducing the percentage of porosity and improving the tissue's tensile strength and elastic modulus. The porosity changes showed a decrease from 72 % to 60 %, and the tensile strength increased from 53.5 kPa to 76 kPa, resulting in an elastic modulus of 510 kPa to 800 kPa. The addition of gum also reduced the rate of destruction of the biological tissue, making it more suitable for soft tissue applications. The obtained results of the pH test showed that the concentration changes were neutral. The contact angle of water droplets was measured to determine hydrophilicity, indicating an improvement in hydrophilicity after the addition of gum. The results showed that the use of PVA and gelatin, due to their ductility and suitable mechanical properties, along with Arabian gum-HA, could accelerate the healing process of dental periodontal problems.

Decorin Inhibits Dermal Mesenchymal Cell Migration and Induces Scar Formation.

Background:Variations in skin healing capacities are observed during different murine embryonic developmental stages. Through embryonic day 16 (E16), embryos are able to regenerate dermal architecture following flank skin wounding; however, after E17, wounds heal incompletely, inducing scar formation. The regenerative ability of the E16 fetal dermis depends on the migration of dermal mesenchymal cells. Decorin is a small molecule known to affect tissue tensile strength, cell phenotype, and tissue repair, including skin wound healing. In the current study, we evaluated the expression and roles of decorin in wound healing.Methods:Surgical injury was induced at E16 and E17 in ICR mouse embryos. Decorin expression was evaluated in tissue samples from these embryos using immunohistochemistry and reverse transcription quantitative polymerase chain reaction. Cell migration assays were used to evaluate wound healing capability of separated dermal and fascial tissues.Results:Our results showed that decorin exhibited distinct expression patterns during wound healing at E16 versus E17. Additionally, decorin expression altered cell migration in vitro. Dermal and fascial mesenchymal cells were found to exhibit distinct migration patterns concomitant with altered decorin expression. Specifically, decorin inhibited migration and favored scar formation.Conclusion:Decorin expression may contribute to scar formation in the late stage of mouse embryos by inhibiting the migration of dermal mesenchymal cells.

EP.TU.659Comparison of Gallbladder Tissue Tensile Strength between Thiel Embalmed Cadavers and Living Patients

Abstract Aim Formalin-embalmed cadavers have traditionally been used as an integral part of anatomy teaching and surgical training. Cadaveric tissue can, however, be compromised by distorted appearance, shrinkage, rigidity and unnatural colouration. The Thiel embalming process produces more ‘life-like’ specimens and it could be postulated that these may be more suitable for surgical training. This study aimed to provide quantifiable and repeatable measurements for the mechanical tissue properties of Thiel embalmed cadavers. Methods Four gallbladders were removed from Thiel Embalmed cadavers and eleven from living patients during laparoscopic cholecystectomies. The specimens were prepared into a uniform ‘hour-glass’ shape. The cadaveric specimens were loaded onto the Instron tensometer and the patient specimens were loaded onto a portable hand-held tensometer. The samples were extended until complete tensile failure occurred allowing measurement of the tissues’ tensile strength and strain. Results Nine samples were obtained from the four Thiel embalmed gallbladders and 27 samples yielded from the 11 living patients’ gallbladders. The mean ultimate tensile strength of the Thiel samples was 2.16 ± 0.91 MPa compared with 2.24 ± 1.40 MPa in the living patient group (p = 0.85). The Thiel embalmed cadaveric samples had a lower measured mean strain than the living patient gallbladders of (123 ± 33% vs. 233 ± 91%, p < 0.01). Conclusion This study demonstrates that, while tissue strength is well preserved, there may be some differences in how the tissues feel, related to differences in elongation during handling in Thiel embalmed gallbladder tissue.

Hemicentin-1 is an essential extracellular matrix component of the dermal\u2013epidermal and myotendinous junctions

The extracellular matrix architecture is composed of supramolecular fibrillar networks that define tissue specific cellular microenvironments. Hemicentins (Hmcn1 and Hmcn2) are ancient and very large members (> 600 kDa) of the fibulin family, whose short members are known to guide proper morphology and functional behavior of specialized cell types predominantly in elastic tissues. However, the tissue distribution and function of Hemicentins within the cellular microenvironment of connective tissues has remained largely unknown. Performing in situ hybridization and immunofluorescence analyses, we found that mouse Hmcn1 and Hmcn2 show a complementary distribution throughout different tissues and developmental stages. In postnatal dermal–epidermal junctions (DEJ) and myotendinous junctions (MTJ), Hmcn1 is primarily produced by mesenchymal cells (fibroblasts, tenocytes), Hmcn2 by cells of epithelial origin (keratinocytes, myocytes). Hmcn1−/− mice are viable and show no overt phenotypes in tissue tensile strength and locomotion tests. However, transmission electron microscopy revealed ultrastructural basement membrane (BM) alterations at the DEJ and MTJ of Hmcn1−/− mice, pointing to a thus far unknown role of Hmcn1 for BM and connective tissue boundary integrity.

Enhanced Skin Incisional Wound Healing With Intracellular ATP Delivery via Macrophage Proliferation and Direct Collagen Production.

This study sought to use a newly developed intracellular ATP delivery to enhance incisional wound healing to reduce surgical wound dehiscence and to explore possible mechanism for this effect. Thirty-five adult New Zealand white rabbits were used. Skin incisions were made on the back and closed. ATP-vesicles were mixed with a neutral cream for one side of the wounds while the neutral cream alone was used on the other side of the wounds. Laser speckle contrast imaging (LSCI), biomechanical, histological, and immunohistochemical analyses were performed 7 and 14 days after surgery, and macrophage culture was used to test the enhanced collagen production ability. Among them, 10 were used for wound perfusion study and 25 were used for wound biomechanical and histological/immunohistochemical studies. Wound tissue perfusion was reduced after surgery especially in early days. Wound tissue tensile strength, breaking stress, and elasticity were all much higher in the ATP-vesicle treated group than in the cream treated group at days 7 and 14. The healing was complemented by earlier macrophage accumulation, in situ proliferation, followed by direct collagen production. The results were further confirmed by human macrophage culture. It was concluded that intracellular ATP delivery enhanced healing strength of incisional wounds via multiple mechanisms.

Polyglactin 910 versus irradiated polyglactin 910 for subcuticular closure in elective surgeries: a randomized double-blind study

Background: All suture materials are treated as foreign bodies and bring out a reaction in the tissues. The severity and duration of response depends on the type of suture material used. The choice of suture material is based on the concept that it should provide adequate tensile strength across the wound until tissue tensile strength has adequately developed, approximation of the epithelial portion has occurred and that the suture material should be absorbed after serving its function. this study was done to compare irradiated polyglactin 910 (Vicryl Rapide) versus polyglactin 910 (Vicryl) for subcuticular skin closure in patients of elective surgeries and to note post-operative wound inflammation, pain, dehiscence and quality of scar.Methods: 60 consecutive patients undergoing elective surgeries in department of surgery SGRD hospital were taken up for the study from April 2020 to June 2020. After randomization the subjects were divided into two groups. Subcuticular skin closure at the end of surgery was done using a 3-0 polyglactin 910 in group A and 3-0 irradiated polyglactin 910 in group B with cutting needle in both groups. Postoperatively the wound was inspected on day 3, 5, 7 and again 3 weeks after surgery.Results: Postoperatively the wounds were observed for the signs of inflammation and infection. Each was given a wound score according to scoring system. Statistical analysis by SPSS 17.0 software and chi-square test. Irradiated polyglactin 910 showed less inflammation, pain and dehiscence along with good quality of scar as compared to polyglactin 910 on comparison.Conclusions: It was concluded that irradiated polyglactin 910 was a better choice for suture material than polyglactin 910 for subcuticular skin closure in terms of postoperative pain, wound dehiscence and quality of scar.

Ethiopian medicinal plants used for their anti-inflammatory, wound healing or anti-infective activities: protocol for systematic literature review and meta-analysis

ObjectivesMedicinal plants are used globally as alternative medicines in the management of a range of disease conditions and are widely accepted across differing societies. Ethiopia hosts a large number of...

Determination the Effectiveness of a selected formulations of Iranian Traditional Medicine “Ushaq poultice” (ammoniacum gum ointment) on Wound Healing: an experimental study

Objective: The purpose of this study was to evaluate the therapeutic effects of ammonium gum ointment on wound healing in the animal model.
 Method: 32 male Wistar rats were selected; then in non-infectious condition, two full-thickness wounds with 8 mm in diameter were created bilaterally on shaved skin in 1.5 cm from the dorsal midline and randomly divided into four groups, untreated group, phenytoin cream treated group, base ointment (sesame oil and wax) treated group and Ammonicuma Gum Ointment (AGO) treated group. The animals received these medicines once daily. On days 5, 7, 10, 12 and 14 wound area was measured. On days 7 and 14, blood samples were taken, and serum level of growth factors (EGF, PDGF, VEGF, and TGF-B) were measured. Skin samples used for hematoxylin-eosin and trichrome staining. Skin tensile strength and hydroxyproline content of skin tissues also measured.
 Results: The percentage of wound healing after 14 days of treatment was significantly increased in the group receiving AGO (PË‚0.05). Hydroxyproline content of repaired tissue and tensile strength increased considerably in this group (PË‚0.001). Growth factors were significantly increased in animals treated with AGO compared to control groups (EGF PË‚0.05; PDGF PË‚0.001; VEGF PË‚0.001; TGF-B PË‚0.05). Histological data showed that the topical application of AGO compared to other groups resulted in positive effects on enhance neovascularization and granulation, increased wound healing rate, and decreased wound size.
 Conclusion: The topical application of an ointment containing ammoniacum gum can help speed up the process of wound healing.

Effects of Hair Follicle Stem Cells on Partial-Thickness Burn Wound Healing and Tensile Strength

Background:The recent improvements in wound healing have led to new strategies in regenerative medicine. Burn wound healing is an important issue in skin regeneration and has multiple indications for stem cell therapy. HFSCs are a highly promising source of stem cells for healing use, as these cells are accessible, active and pluripotent adult stem cells. Methods:HFSCs of the rat whisker were isolated, cultured, and labeled with DiI. Flow cytometry method was used to detect special markers of HFSCs. Deep partial-thickness burn wound was created, and labeled HFSCs were injected around the wound bed. Wound closure was recorded via digital photographs. The inflicted rats were sacrificed at 3, 7, or 14 days post burn and used for subsequent histological and tensiometry analysis. Results:Our results indicated that HFSCs were positive for Nestin and CD34 markers, but negative for Kr15. Morphological and histological photographs revealed that wound closure rate was accelerated in stem cell-treated group compared with other groups. In addition, faster re-epithelialization and collagen deposition were observed. The immunohistochemical analysis suggested that CD31 expression and vascular density enhanced in the stem cell-treated group. Further, tissue tensile strength increased in HFSCs-treated rats in comparison to the control group. Conclusion:The present study demonstrates that HFSCs could accelerate burn wound healing as well as tensile strength in rats.

Ultrasound Imaging of the Superficial Fascial System Can Predict the Subcutaneous Strength of Abdominal Tissue Using Mean Gray Value Quantification.

This study is the first to correlate sonographic findings of subcutaneous tissue to structural and biomechanical properties. Precisely sized tissue specimens (59 samples) were collected from five abdominoplasty procedures. A Philips Lumify L12-4 linear array probe, connected to an Android tablet, was used to obtain ultrasound images of the superficial fascial system. A no. 1 Vicryl suture on a CTX needle placed though a needle guide within a three-dimensionally printed template ensured equal bites of subcutaneous tissue across specimens. Suture pull-out strength was measured until failure at a displacement rate of 2.12 mm/second using an Admet MTEST Quattro. Mean gray value for the superficial fascial system in associated ultrasonographic images was quantified by CellProfiler. Superficial fascial system visualization can be accomplished using high-resolution portable ultrasound. Comparing multiple specimens' imaging, interpatient and intrapatient variability of superficial fascial system quantity and structural characteristics are apparent. The superficial fascial system is highly abundant in some patients, but has limited presence in others. Individual-specimen mean gray value and whole-patient mean gray value positively correlated with tissue tensile strength (p = 0.006) and patient-average tissue tensile strength (p = 0.036), respectively. Whole-patient mean gray value accounted for 98.5 percent of the variance seen in patient-average tensile strength, making it a strong predictor for tensile strength. Portable ultrasound and image-processing technology can visualize, quantify, and predict subcutaneous tissue strength of the superficial fascial system. The superficial fascial system quantity correlates with suture tensile strength. Clinically, preoperative superficial fascial system quantification may aid in outcome predictions, manage patient expectations, and potentially lower complication rates. Diagnostic, V.

THE FEATURES OF THE FACE SKIN CONSTRUCTION THAT INFLUENCE ON THE FORMATION OF CICATRICAL TISSUES DURING SUGICAL INTERVENTIONS

Formation of pathological scars of maxillofacial localization after surgery is a significant and widespread problem of modern surgical stomatology and maxillofacial surgery. A significant percentage of patients who needs planned and urgent surgical interventions cause rapid development of reconstructive-restorative surgery of the maxillofacial region.
 The analysis of domestic and foreign literary sources was devoted to the peculiarities of the structure of the skin of the head and neck and the optimization of the skin incisions of this localization.
 Functional features of human skin depend on the mechanical properties of the dermis, which provides elasticity and resistance to stretching. Changes in the biomechanics of the dermis occur during aging, excessive insolation, scarring, and fibrosis. In addition, mechanical changes in the extracellular matrix of the skin affect the activity and phenotype of the fibroblasts, which adapt the stiffness of the cytoskeleton. Extracellular matrix stiffness defines and maintains cell identity and influences the proliferation, differentiation, migration and expression of skin cells.
 The extracellular matrix has been regarded for a long time as a structure with simple architectonics. But, due to modern research, it is known that this complex formation is highly specialized. The different classes of macromolecules that make up the extracellular matrix determine its biological functions. For example, collagen proteins are responsible for the tensile strength of tissues, proteoglycans and glycosaminoglycan are important for hydration and compression resistance, and glycoproteins such as laminas facilitate cell attachment. The largest structures of the extracellular matrix are elastin fibers, which are mainly localized in tissues subject to high mechanical stress, such as skin, lungs, or arteries. These structures represent a very complex organization whose core consists of elastin surrounded by a mantle of microfibrils.
 Collagen proteins in the dermis contain mainly type I collagen (85% - 90%) with smaller amounts of type III collagen (10% - 15%). Skin fibroblasts synthesize individual collagen type I and III polypeptide chains as precursor molecules, called procollagens. During the formation of insoluble collagen fibrils, specific proteases break down the carboxy- and amino-terminal domains, forming pN-collagen (procollagen from which the carboxy-terminal domain propeptide is cleaved) and pC-collagen (procollagen, from which the amino-terminal propeptide is cleaved). Because type I and III procollagen, pN-collagen and pC-collagen are precursors of mature collagen molecules, their level usually reflects the level of collagen biosynthesis.
 Collagens and elastin contain highly abundant fibrils, each of which is repeated in a sequence enriched in the conformation of polyproline II, cross-linked, insoluble in assembly and resistant to the most photolytic enzymes. The monomeric block of type I collagen consists of two extended chains α1 and one chain α2, twisted together into a triple helix.
 The direction of collagen and elastin fibers, according to biomechanical studies, has a significant effect on the enlargement of the wound on the head skin and the tension when closing its edges. The overwhelming reduction of tension and accordingly the improvement of reparative processes in the skin occur when the incision lines correspond to the so-called "golden spiral".
 Conclusion. Thus, the analysis of domestic and foreign literature sources indicates the relevance of the selected topics, the need for further studies on the biomechanical and histological substantiation of incisions, which are due to the peculiarities of the structure of the skin in the head and neck to create optimal conditions for reparative regeneration.

Collagen (XI) alpha-1 chain is an independent prognostic factor in breast ductal carcinoma in situ

Collagen11A1 (COL11A1) is a fibrillary type collagen constituting a minor component of the extracellular matrix and plays role in tissue tensile strength. Overexpression of COL11A1 expression is associated with aggressive behavior and poor outcome in several human malignancies. In this study, we evaluated the association between COL11A1 expression and clinicopathological parameters of the breast ductal carcinoma in situ (DCIS) and its prognostic value. COL11A1 protein expression was assessed immunohistochemically in a large well-characterized cohort of DCIS including pure (n = 776) and DCIS associated with invasive carcinoma (DCIS-mixed, n = 239). COL11A1 expression was assessed in tumor cells and surrounding stromal cells, and correlated with clinicopathological parameters, immunoprofile and disease outcome. In pure DCIS, high COL11A1 expression was observed in tumor cells and surrounding stromal cells in 25 and 13% of cases, respectively. Higher COL11A1 expression within the stromal cells was associated with hormone receptor negative, HER2 enriched and triple negative molecular subtypes and showed a positive linear correlation with proliferation index, dense tumor infiltrating lymphocytes and hypoxia-inducible factor 1 alpha. COL11A1 expression in tumor and stromal cells was significantly higher in DCIS associated with invasive carcinoma than in pure DCIS, and within the DCIS-mixed cohort, the invasive component showed higher COL11A1 expression than the DCIS component (all, p < 0.0001). Overexpression of stromal COL11A1 was an independent predictor of shorter local recurrence-free interval for all recurrences (HR = 13.2, 95% CI = 6.9–25.4, p < 0.0001) and for invasive recurrences (HR = 11.2, 95% CI = 4.9–25.8, p < 0.0001). When incorporated with other risk factors, stromal COL11A1 provided better patient risk stratification. DCIS with higher stromal COL11A1 expression showed poor outcome even with adjuvant radiotherapy management. In conclusion, overexpression of stromal COL11A1 is associated with invasive recurrence in DCIS and is a potential marker to predict the response to radiotherapy.

Modeling the nonlinear elastic behavior of plant epidermis

Cell growth and organ development in plants are often correlated with the tensile behavior of the primary cell wall. To understand the mechanical behavior of plant material, various mechanical testing techniques have been employed, such as tensile testing of excised tissue samples. The onion (Allium cepa L.) epidermis has emerged as a model system for plant tissue mechanics. In this study, we performed tensile tests on strips of adaxial onion epidermis. While the tissue appeared stiffer in the direction along the major growth axis compared with the transverse direction, the tensile strength of tissue was not significantly different between the two orientations, indicating a nontrivial link between the cell wall and tissue mechanical anisotropy. Importantly, we observed the stress–strain behavior of the onion epidermis under tension to be highly nonlinear. Several hyperelastic models were fitted to the test data to evaluate their capacity to describe the nonlinear deformation of onion epidermis. The Yeoh hyperelastic model could successfully simulate the uniaxial tensile test data. This study suggests that accounting for nonlinearity in the deformation of the primary tissue may be essential for the accurate interpretation of mechanical test data, and a better understanding of the mechanics of the primary plant cell wall.

In Vivo Comparison of MONOFIX, A Novel Barbed Suture with a Triangular Stopper, with Pre-existing Products in a Porcine Model

Study ObjectiveMONOFIX, a new absorbable barbed suture device, has a triangular stopper at the end to hold the suture to the tissue without hooking the looped end or knotting. The aim of this study was to compare the biomechanical strength and histologic features of MONOFIX with other barbed suture devices using a porcine model. DesignWell-designed, controlled trial without randomization. SettingAnimal laboratory in university hospital. SubjectsSixteen, 60-kg, mature female domestic pigs (skin closure group) and 5, 60-kg, mature female domestic pigs (fascial closure group). InterventionsIn the skin closure group, 3-0 MONOFIX versus 2 widely used 3-0 absorbable barbed sutures (3-0 V-Loc 180 or Stratafix). In the fascial closure group, 2-0 MONOFIX versus 1 widely used 2-0 absorbable barbed sutures (2-0 Stratafix). Measurements and Main ResultsIn the skin closure group, the biomechanical wound strength of skin sutured with size 3-0 MONOFIX, V-Loc 180, or Stratafix was evaluated by postoperative day assessment (days 0, 3, 7, 14, and 28). In the fascial closure group, pigs underwent 2 paramedian incisions and were sutured with 2-0 MONOFIX or with 2-0 Stratafix to evaluate histologic reaction. At 6 weeks the tissues around the suture line were excised and microscopically evaluated. The biomechanical strength of the MONOFIX had similar tissue tensile strength compared with the control, regardless of postoperative day. In the fascial closure model, there was no significant difference in the average tissue reaction score between MONOFIX and Stratafix (1.2 ± .3 vs 1.3 ± .3, p = .478). ConclusionThis study demonstrated that MONOFIX has equivalent tensile strength and histologic reaction when compared with commonly used barbed suture devices. Accordingly, this preclinical study suggests that the use of MONOFIX is a safe alternative to other barbed suture devices.

Wound Healing Activity of Alcoholic Extract of Tamarix Aphylla L. on Animal Models

To evaluate the wound healing activity of ethanolic extract of Tamarix aphylla L. on animal model. Wound creation like circular excision and linear incision method were considered for this study. The various parameters were studied like DNA estimation, total protein estimation, estimation of Hexosamine and Uronic acid, estimation of lipid peroxides and antioxidant activity, Tensile Strength of tissues from incision wounds, Antioxidant activity, Antimicrobial activity, Period of epithelialization and finally TNF-a concentration in the wound tissue homogenate were estimated. The treatment groups with the extract showed significant antimicrobial activity with compare to the standard drug. Significantly, 93. 86% increase in the collagen content and significant 52% up regulation in tensile strength was observed in the treated group. 40% reduction was observed in epithelialization period of the treated wounds. The results of the current study confirm that the ethanolic extract of T. aphylla has potent wound healing capacity.

Structural and mechanical characteristics of collagen tissue coated with chitosan in a liquid CO2/water system at different pressures

Chitosan coatings of biological heart-valve prostheses enhance their biocompatibility, resistance to pathogenic microflora and lifetime. Collagen tissues can be coated with chitosan in aqueous solution acidified, to make chitosan soluble, with H2CO3 formed from a coexisting liquid CO2 phase under pressure. The advantage of H2CO3 is that it can be easily removed after the coating procedure. This study assessed the effects of 6–50 MPa CO2 pressure during the coating procedure on the structure and mechanical properties of the resulting biocomposite matrices. The dependence of chitosan adsorption on CO2 pressure was bell-shaped, reaching a maximum adsorption of 0.8 mass % at 40 MPa. Tissue surface became highly porous upon pressure treatment. At 50 MPa, the pores merged to form furrows with lengths of several hundred micrometers, accompanied by collagen fibril reorganisation. Chitosan coating did not affect tissue tensile strength in the axial direction, but increased it by 75% in the radial direction in the tissue coated at 50 MPa pressure. Strain at break, a measure of elasticity, increased in both directions by up to 100% upon coating with chitosan. CO2 pressure of 30–50 MPa seems thus optimal in terms of chitosan incorporation and tissue mechanical properties.

Excision wound healing activity of a common biosurfactant produced by Pseudomonas sp.

Abstract Background Wound is an inherent process to regenerate the cellular cohesion of tissue. Present study deal with the accelerating potentiality of rhamnolipid produced by P. aeruginosa C2 using fat of Catla catla fish as an economic substrate to heal wound in a shorter time. Methodology An ointment containing rhamnolipid (5 g/l) was administered on the back of each wister rat after creating excision wound of 50 mm2. The examined parameters were percentage wound reduction, tissue tensile strength, DNA, protein, hexosamine content and histological study of regenerated tissue and TNF α estimation from blood serum. Main findings Rhamnolipid enhanced the rate of wound contraction within 10 days in comparison to untreated control group (p Conclusions The results of this study have expressed that rhamnolipid can be used as a wound healing material for excision wound. Rhamnolipid can provide additional advantage in healing by showing protection from bacterial infection.