scholarly journals Treatment with type-I collagen scaffolds in patients with venous ulcers. Case report

Case reports ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 128-136
Author(s):  
Martha Isabel González-Duque ◽  
Julián Daniel Hernández-Martínez ◽  
Marta Raquel Fontanilla ◽  
Sofía Elizabeth Muñoz-Medina

Introduction: Chronic venous insufficiency affects about 5% of the global adult population. Venous leg ulcers are one of the most frequent complications of this pathology, with a global prevalence of 2%. This disease affects both the quality of life of patients and, due to the high cost of the treatment, the health system. Compressive therapy and moist wound healing have been the gold standard treatment. However, when complications occur, they may not be effective.Case report: This is the case of a 66-year-old female patient with venous ulcers on her lower limbs and symptoms of fever and local pain that did not respond to conventional therapies. The patient was treated with a new dermal substitute made of an acellular type-I collagen membrane, which promotes the closure of the ulcer by stimulating the replacement of injured tissue with tissue similar to the healthy one. The condition of the patient improved at 16 weeks, and after 8 months of treatment there was no recurrence of the lesions.Conclusions: Acellular type-I collagen membrane developed by the Tissue Engineering Working Group of the Department of Pharmacy of the Universidad Nacional de Colombia is effective in treating venous ulcers of the lower limbs. Its low cost facilitates the access of the whole population to therapies based on its application.

Author(s):  
Lucas Félix ROSSI ◽  
Manoel Roberto Maciel TRINDADE ◽  
Armando José D`ACAMPORA ◽  
Luise MEURER

ABSTRACT Background: Hernia correction is a routinely performed treatment in surgical practice. The improvement of the operative technique and available materials certainly has been a great benefit to the quality of surgical results. The insertion of prostheses for hernia correction is well-founded in the literature, and has become the standard of treatment when this type of disease is discussed. Aim: To evaluate two available prostheses: the polypropylene and polypropylene coated ones in an experimental model. Methods: Seven prostheses of each kind were inserted into Wistar rats (Ratus norvegicus albinus) in the anterior abdominal wall of the animal in direct contact with the viscera. After 90 days follow-up were analyzed the intra-abdominal adhesions, and also performed immunohistochemical evaluation and videomorphometry of the total, type I and type III collagen. Histological analysis was also performed with hematoxylin-eosin to evaluate cell types present in each mesh. Results: At 90 days the adhesions were not different among the groups (p=0.335). Total collagen likewise was not statistically different (p=0.810). Statistically there was more type III collagen in the coated polypropylene group (p=0.039) while type I was not different among the prostheses (p=0.050). The lymphocytes were statistically more present in the polypropylene group (p=0.041). Conclusion: The coated prosthesis was not different from the polypropylene one regarding the adhesion. Total and type I collagen were not different among the groups, while type III collagen was more present on the coated mesh. There was a greater number of lymphocytes on the polypropylene mesh.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 480 ◽  
Author(s):  
Massimo Lucarini ◽  
Alessandra Durazzo ◽  
Fabio Sciubba ◽  
Maria Enrica Di Cocco ◽  
Raffaella Gianferri ◽  
...  

The water-holding capacity (WHC) is among the key factors in determining the quality of meat and its value, which is strongly influenced by the content and quality of the connective tissue proteins like collagen. Therefore, the factors that influence the proteins’ stability, e.g., pH, ionic strength, and the antioxidants which are used to increase the meat shelf-life, also affect the WHC. The interaction of collagen, whose structure is strongly influenced by the interaction with water molecules, can be studied following the behavior of water diffusion by low-resolution 1H NMR experiments. The present study is addressed to study the collagen stability as a function of pH, ionic strength, and phenolic antioxidants like catechin. The experimental study demonstrated how the 1H NMR time domain (TD) experiments are able to evaluate the hydration properties of collagen, not only as a function of ionic strength and pH, but also in determining the ability of catechin to interact both on the surface of the collagen fibrils and inside the fibrillar domain.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3118
Author(s):  
Jeimmy González-Masís ◽  
Jorge M. Cubero-Sesin ◽  
Yendry R. Corrales-Ureña ◽  
Sara González-Camacho ◽  
Nohelia Mora-Ugalde ◽  
...  

Propolis natural extracts have been used since ancient times due to their antioxidant, anti-inflammatory, antiviral, and antimicrobial activities. In this study, we produced scaffolds of type I collagen, extracted from Wistar Hanover rat tail tendons, and impregnated them with propolis nanoparticles (NPs) for applications in regenerative medicine. Our results show that the impregnation of propolis NPs to collagen scaffolds affected the collagen denaturation temperature and tensile strength. The changes in structural collagen self-assembly due to contact with organic nanoparticles were shown for the first time. The fibril collagen secondary structure was preserved, and the D-pattern gap increased to 135 ± 28 nm, without losing the microfiber structure. We also show that the properties of the collagen scaffolds depended on the concentration of propolis NPs. A concentration of 100 μg/mL of propolis NPs with 1 mg of collagen, with a hydrodynamic diameter of 173 nm, was found to be an optimal concentration to enhance 3T3 fibroblast cell metabolic activity and cell proliferation. The expected outcome from this research is both scientifically and socially relevant since the home scaffold using natural nanoparticles can be produced using a simple method and could be widely used for local medical care in developing communities.


2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Bin Xu ◽  
Ming-Jay Chow ◽  
Yanhang Zhang

Collagen type I scaffolds are commonly used due to its abundance, biocompatibility, and ubiquity. Most applications require the scaffolds to operate under mechanical stresses. Therefore understanding and being able to control the structural-functional integrity of collagen scaffolds becomes crucial. Using a combined experimental and modeling approach, we studied the structure and function of Type I collagen gel with the effects of spatial fiber alignment and crosslinking. Aligned collagen scaffolds were created through the flow of magnetic particles enmeshed in collagen fibrils to mimic the anisotropy seen in native tissue. Inter- and intra- molecular crosslinking was modified chemically with Genipin to further improve the stiffness of collagen scaffolds. The anisotropic mechanical properties of collagen scaffolds were characterized using a planar biaxial tensile tester and parallel plate rheometer. The tangent stiffness from biaxial tensile test is two to three orders of magnitude higher than the storage moduli from rheological measurements. The biphasic nature of collagen gel was discussed and used to explain the mechanical behavior of collagen scaffolds under different types of mechanical tests. An anisotropic hyperelastic constitutive model was used to capture the characteristics of the stress-strain behavior exhibited by collagen scaffolds.


2005 ◽  
Vol 897 ◽  
Author(s):  
David I Shreiber ◽  
Harini G Sundararaghavan ◽  
Minjung Song ◽  
Vikram Munikoti ◽  
Kathryn E Uhrich

AbstractIt is now well accepted that the mechanical properties and cell adhesion profile of 2D and 3D extracellular matrix molecules combine to dictate cellular fate processes, such as differentiation, migration, proliferation, and apoptosis, through a process generally known as 'mechanotransduction', or the conversion of mechanical signals into a cellular response. The stiffness and adhesion density combine to affect the force balance that exists between an adherent cell and the surrounding substrate. We have established BioMEMS, microfluidic technology to alter the mechanical properties and cell adhesion profile of collagen scaffolds. Using soft lithography, we fabricate elastomeric networks that serve as conduits for the controlled mixing of type I collagen solutions. Our technology enables us to generate reproducible, controlled homogeneous and inhomogeneous microenvironments for 3D cell culture, assays of cell behavior in 3D, and the development of bioartificial tissue equivalents for regenerative and reparative therapies. The adhesivity of collagen is modulated by covalently grafting peptides (such as RGD) or proteins (such as albumin) to soluble collagen molecules with 1- ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC), a hetero-bifunctional coupling agent. EDC activates the carboxylic group of collagen and forms an amine bond with the grafting molecule. The grafted collagen self-assembles into a fibrillar gel at physiological temperature and pH with no measurable changes in rheological properties compared to controls. A solution of peptide-grafted collagen is then mixed in microfluidic networks with unaltered collagen to form controlled gradients or other patterns of the two solutions, which immobilize upon self-assembly. Separately or in the same network, the mechanical properties of the collagen gel can be altered regionally by the microfluidic delivery a solution of a cell-tolerated crosslinking agent. We use genipin, which has the unique property of generating crosslinks that autofluoresce. The intensity of the fluorescence correlates with the degree of crosslinking (and thus the mechanical properties) enabling us to monitor and measure changes in mechanical properties dynamically and non-invasively. Lastly, though it requires constant delivery or recirculation, the same networks can be used to impose gradients of soluble factors, such as growth factors and cytokines. Thus, we have developed a platform to examine the response of cells to simultaneous chemotactic, haptotactic, and durotactic gradients in a 3D environment. We are employing this technology to examine the response of neural cells to gradients of biomaterial properties to optimize cues for spinal cord regeneration.


Author(s):  
Albert O. Gee ◽  
Brendon M. Baker ◽  
Robert L. Mauck

Collagen is a principal constituent of the extracellular matrix (ECM) and as such, defines the microenvironmental milieu in which cells reside. In fiber-reinforced musculoskeletal tissues, collagen fibers are highly organized and generate the direction-dependent mechanical properties critical to the function of these structures. Given its primary role, collagen is particularly attractive for tissue engineering (TE) applications where scaffolds are coupled with cells to repair or regenerate damaged tissues. One method for producing collagen-based scaffolds is through electrospinning. This technique yields nano- to micron-scale fibers similar in diameter to those of the native ECM. Towards engineering orthopaedic tissues, methods have been devised to electrospin fibers into aligned arrays that can recapitulate the anisotropy of fiber-reinforced tissues [1]. While a number of polymers have been electrospun, collagen-based scaffolds are especially promising as they provide a biomimetic interface for cell attachment [2]. Numerous investigators have electrospun collagen [3], one major drawback is their inherent instability in aqueous environments. To address this, various crosslinking agents including glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, and N-hydroxysuccinimide chemistries have been used, but these chemicals often prove cytotoxic or excessively laborious in application [4]. Even with crosslinking, dry as-formed nanofibrous collagen scaffolds with moduli greater than 50MPa diminish by 100-fold with rehydration [5].


2014 ◽  
Vol 15 (4) ◽  
pp. 531-541 ◽  
Author(s):  
Xiujie Zhang ◽  
Xueying Chen ◽  
Ting Yang ◽  
Naili Zhang ◽  
Li Dong ◽  
...  

2011 ◽  
Vol 493-494 ◽  
pp. 844-848 ◽  
Author(s):  
Marcia S. Sader ◽  
Gutemberg Alves ◽  
Racquel Z. LeGeros ◽  
Gloria Dulce de Almeida Soares

Natural bone constitutes of an inorganic phase (a biological nanoapatite) and an organic phase (mostly type I collagen). The challenge is to develop a material that can regenerate lost bone tissue with degradation and resorption kinetics compatible with the new bone formation. The aim of this study was to prepare self-organized magnesium and carbonate substituted apatite/collagen scaffolds, cross-linked with glutaraldehyde (GA). Bovine tendon was submitted to alkaline treatment resulting in a negatively charged collagen surface. The scaffolds were prepared by precipitation: simultaneous dropwise addition of solution containing calcium (Ca) and magnesium (Mg) ions and collagen into a buffered solution containing carbonate and phosphate ions in reaction vessel maintained at 37 °C, pH=8. The reaction products were cross-linked with 0.125 and 0.25% (v/v) glutaraldehyde (GA) solution and freeze-dried. The samples were characterized by Fourier-transformed infrared spectroscopy (FTIR). In vitro cytotoxicity (based on three parameters assays) and scaffolds degradation in culture medium and osteoblastic cells culture were performed in the cross-linked materials. No cytotoxic effects were observed. The cross-linked samples with the lower GA concentration showed a lower stability when placed in contact with culture medium. Human osteoblasts attached on the scaffolds surface cross-linked with 0.25% GA, forming a continuous layer after 14 days of incubation. These results showed potential application of the designed scaffolds for bone tissue engineering.


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