Collagen fibres from reindeer tendons can be used to create threads. These threads have traditionally been used in Sápmi crafts. Due to the high cost of manual extraction, tendon-based threads have been replaced with cheaper synthetic threads. However environmental concerns have been raised within the Sápmi crafts communities regarding the synthetic threads. To mitigate the impacts of synthetic threads and to better utilize the reindeer after slaughter a more efficient fibre extraction process has been sought after. In this study two venues have been investigated, softening and retting. In this study softening will refer to the breaking of bonds through the use of a liquid. Retting will refer to a controlled degradation of a material through biological processes. Softening and retting aided mechanical extraction of collagen fibres. The softening, using water and in some cases polyethylene glycol, reduced entanglement and friction. The retting can be divided into short term retting and long-term retting, up to six weeks. Neither the short-term retting nor the long-term retting did facilitate the extraction significantly compared to a simpler softening treatment. Softening on the other hand made extraction easier. A 70 hour softening with water at room temperature had the largest impact. The extraction became slightly easier when the samples were further softened with polyethylene glycol. This was compared to a reference sample where water was used for further softening. Mechanical fibre extraction methods were also evaluated. The softened tendon samples were calendered between two rollers at 1.2 bar and 5.0 bar. The samples using the higher pressure were easier to separate. The samples were then manually torn apart into fine fibre bundles. Many of the manual methods used can be automated but they would need specialized equipment. The mechanically extracted fibres were then spun into yarns through hand spinning with moistened fingers. The tensile properties of the fibres and the yarns were determined. The fibres and the yarns were also evaluated through light microscopy. Both the yarns and fibres showed a high degree of variation in the tensile tests. The use of manual methods likely contributed to the high variation. The yarns slipped which caused a lower tenacity compared to the fibres. The mean fibre tenacities were between 17-20 cN/tex, depending on factor. Neither of the factors were significantly different. The elasticity of the fibres varied to a large extent. The fibres exhibited an almost fully elastic deformation until break. The fibres were white to cream and slightly translucent when viewed in a light microscope. The yarns were uneven and glossy.

Hereditary equine regional dermal asthenia (HERDA) is a recessive connective tissue disorder of Quarter Horse lineages. This study correlates previously identified decreases in skin tensile strength in HERDA with abnormal dermal collagen cross linking patterns that are also identified in urine from HERDA horses. Dermal collagen from HERDA horses has significantly less pyridinoline and significantly more deoxypyridinoline than control or carriers. Concentrations of hydroxylysine, the rate limiting substrate for these crosslinks were significantly lower in HERDA versus control and carriers. These characteristics of HERDA skin parallel humans with a similar syndrome of skin fragility, Ehlers Danlos Syndrome TypeVIA. This is the first biochemical evidence explaining the clinical skin fragility that characterizes HERDA and suggests that altered collagen lysine metabolism may be physiologically relevant to the clinical manifestation of HERDA. Evaluations of mature scars indicate that lesion and nonlesioned skin should not be viewed as biologically equivalent in HERDA investigations.

Objective: Anterior cruciate ligament (ACL) injuries are increasing in adolescents and increase the risk for early-onset knee osteoarthritis (OA). Biomarkers can be a non-invasive measure to assess physiological properties following knee injury or trauma. The objective of this thesis was to i) perform a systematic review to determine the most studied biomarkers of knee healing following ACL reconstruction (ACLR), and age of these patients, and ii) explore the feasibility of measuring these biomarkers in adolescents with ACL injuries. Design: Studies were included if i) participants underwent ACLR, and ii) at least one biomarker of healing was measured. Participant age, sample(s) collected, and biomarker(s) studied were recorded. Interleukin-6 (IL-6), c-terminal crosslinking telopeptide of type II collagen (CTX-II) and procollagen type II collagen propeptide (PIICP) were then measured using ELISA in adolescents prior to ACLR in urine (u) and synovial fluid (sf). Spearman’s Rho (rs) coefficients were calculated to determine the association between uCTX-II/sfCTX-II, and uIL-6/sfIL-6. A ratio of PIICP: CTX-II was calculated to represent the ratio of cartilage synthesis to degradation. Results: The review produced six studies evaluating healing following ACLR. IL-6 and CTX-II were the most studied (3/6 studies), and only one study included adolescents (age 19.6±4.5). Due to multiple undetectable biomarker levels, we could only report rs for uCTX-II/sfCTX-II (rs = -.200, p-value = .800, n=4). We also reported a ratio for sfPIICP: sfCTX-II (23.06 ±19.23). Conclusion: Exploring biomarkers in adolescents was motivated by their unique physiology due to puberty, and this was the first study to do so. The findings from this pilot study indicate that further analysis is required to determine optimal sample preparation. This will allow for reliable results while studying the feasibility of these biomarkers during ACLR recovery. This insight can ensure more informed decision making by clinicians clearing patients for return-to-activity.

Indiana University-Purdue University Indianapolis (IUPUI) / Rationale: Tissue remodeling and complement activation are asthma hallmarks. Type V collagen [col(V)], a cryptic antigen, becomes exposed during lung remodeling. IL-17 is key to anti-col(V) immunity, and regulates complement activation. We have reported that col(V)-induced tolerance down regulates IL-17 and prevents immune-mediated lung diseases. Objectives: Determine a role for anti-col(V) immunity in asthma. Methods: Serum anti-col(V) antibodies were measured in asthma patients, and immunohistochemistry utilized to detect interstitial col(V) in fatal asthma. Balb/c mice were tolerized with col(V) prior to sensitization with ovalbumin (OVA), and subsequent OVA intranasal challenge. Airway hyper-responsiveness (AHR) to methacholine was measured; and RT-PCR utilized to determine local Il17 transcripts. Bronchoalveolar lavage levels of C3a¸ C5a and OVA-specific IgE were measured; and immunohistochemistry utilized to detect expression of complement regulatory proteins, expression, CD46/Crry and CD55, in lung tissue. Results: Compared to normal subjects, anti-col(V) antibodies were increased in asthmatics; and interstitial col(V) was over expressed in fatal asthma. OVA-induced AHR up regulated anti-col(V) antibodies systemically, and increased OVA-specific IgE and C3a in BAL, and parenchymal Il17 transcripts. Col(V)-induced tolerance abrogated AHR, down regulated OVA-induced T cell proliferation, as well as total and OVA-specific IgE, C3a, IL-17 expression and tracheal smooth muscle contraction. Crry/CD46 and CD55, key to preventing complement activation, were down regulated on goblet cells in murine allergic airway disease. Conclusions: Anti-col(V) immunity correlates with asthma pathogenesis, and col(V)-induced tolerance may be a novel therapeutic for asthma. Decreased expression of Crry/CD46 and CD55 on goblet cells may in part account for complement activation in asthma.

No description available.

<p>   </p> <p>Subcutaneous injection is a biotherapeutic drug delivery method that is currently growing due to low cost, better patient compliance, minimally invasive, and the convenience that it can be done at home. Common injection sites for subcutaneous injection include the upper outer arms, abdomen, buttocks, and upper outer thigh. Heterogeneity of the tissue exists between and within each of these locations. The subcutaneous tissue space is made up of adipose tissue, proteins, collagen, and blood vessels and each of these components has an impact on the mass transport of the injected biotherapeutics and how they are absorbed into the vascular system and then distributed to the body. The current methods used to model the subcutaneous tissue space are either very expensive and not feasible for multiple repetitions, cannot incorporate fibrillar proteins or cellular components, or model a more homogeneous tissue space. These limitations do not allow for these models to accurately represent the subcutaneous tissue space. The engineering objective for this project was to develop a platform with tunable matrix architecture and biochemical composition for evaluating mass transport. This project utilizes collagen and the primary matrix due to the large abundance of collagen in the body.  We explored the effects that a change in polymerization temperature of the collagen and collagen concentration had on the fiber architecture and pore diameter. The results showed that higher polymerization temperatures of the collagen gels resulted in smaller fiber and pore diameters and an increase in concentration resulted in an increase in fiber volume fraction and a decrease in pore diameter. Fibronectin (FN) and hyaluronic acid (HA) were added to the collagen gels to analyze the impact on the structure of collagen gels with a change in polymerization temperature and collagen concentration. The addition of FN did not strongly alter the collagen fiber architecture between polymerization temperatures and collagen concentrations. Through staining and imaging, we saw an aggregation of FN around the collagen fibrils due to their opposing charges causing them to bind. The addition of HA had moderate impact on collagen fiber architecture across all polymerization temperatures and between collagen concentrations. The collagen + FN gels were used for the mass transport study. The results showed that there was little to no difference between the recovery rates of macromolecules of different charges and size between the collagen and collagen + FN gels, indicating that the transport of molecules through both of the collagen gels was impacted by a steric effect rather than an effect in charge.</p> <p>  </p>

Cardiovascular disease (CVD) is ranked the second leading cause of death in Canada, with 53,704 heart disease-related deaths documented in 2020 alone. After a patient sustains cardiac injury, such as a myocardial infarction (MI), the heart is often unable to undergo sufficient self-recovery for healthy cardiac regeneration and repair; this is largely attributed to fibrotic tissue development at the injury site and subsequent pathological ventricular remodeling. The prevalence of MI events has created a considerable demand to develop novel strategies for effective and safe post-MI therapies. Research has indicated that post-MI modifications interfere with endogenous cardiac repair mechanisms, resulting in a pathological state. After an infarction, there is an accumulation of methylglyoxal (MG) at the site of injury. It has been suggested that MG contributes to ventricular fibrotic development, however its underlying mechanism remains unclear. Additionally, the effects that the post-MI cardiac environment, specifically MG accumulation, has on post-MI therapies and biomaterials has not been sufficiently established. Accordingly, the primary focus of this research project is to elucidate the effects of MG on the collagen-rich extracellular matrix (ECM) of the heart and key cardiac cells involved in the repair process. Further, the interaction between MG and a promising collagen-based hydrogel therapy is investigated, exploring the effects of MG on the hydrogel’s degradative process. It was found that the MG modification of hydrogels did not alter the degradation rate. Additionally, the degradation products of hydrogels, and MG-modified substrates did not affect the properties and formation of myofibroblasts.

In der vorliegenden Arbeit wurde der Einfluss der humanen AT2-Rezeptorexpression und -stimulation auf den Collagen I alpha 2-mRNA-Gehalt und die Migration von porcinen kardialen Fibroblasten untersucht, um die Frage zu klären, ob AT2-Rezeptoren in kultivierten kardialen Fibroblasten AT1-antagonistische antifibrotische und migrationshemmende Effekte auf den Collagen I alpha 2-mRNA-Gehalt bzw. die Migration ausüben. Um die Funktion der AT2-Rezeptoren in der Zellkultur untersuchen zu können, wurde die AT2-cDNA durch adenovirale Transduktion in die Fibroblasten übertragen und so der AT2-Rezeptor überexprimiert. Mittels RT-PCR wurden die relativen Änderungen im Collagen I alpha 2-mRNA-Gehalt in TGF-beta1- bzw. TGF-beta1 plus Ang II-stimulierten Fibroblasten im Vergleich zur unstimulierten Kontrolle bestimmt. Alle Werte wurden auf ein Referenzgen (beta-Actin) bezogen. Die AT2-Stimulation änderte den relativen Collagen I alpha 2-mRNA-Gehalt der Fibroblasten nicht signifikant gegenüber den Antisense-(Ad5TA2)-transduzierten Fibroblasten. In der modifizierten Boyden-Kammer wurde der AT2-vermittelte Effekt von Ang II, hPDGF-BB sowie der Kombination beider Stoffe auf die Migration untersucht. Die alleinige Stimulation von AT2-Rezeptoren mit Ang II verhinderte die Migration gegenüber nichttransduzierten Fibroblasten. In Kombination mit hPDGF-BB änderte Ang II die Migration in AT2-überexprimierenden Fibroblasten nicht gegenüber den Antisense-(Ad5TA2)-transduzierten Fibroblasten. Bei ausschließlicher Stimulation durch hPDGF-BB wurde aber in AT2-exprimierenden Fibroblasten eine signifikant geringere Migration als in Antisense-(Ad5TA2)-transduzierten Fibroblasten festgestellt. Die zugrunde liegende Hypothese, dass AT2-Expression und Stimulation den relativen Collagen I alpha 2-mRNA-Gehalt hemmt, konnte in den vorliegenden Experimenten nicht bestätigt werden. Dies ließ keine inhibitorische AT2-vermittelte Wirkung von Ang II im Bezug auf den TGF-beta1-induzierten Collagen I alpha 2-mRNA-Gehalt erkennen. Dagegen führte die Ang II-Stimulation überexprimierter AT2-Rezeptoren zu einer verringerten Migration und vermittelte so einen AT1-antagonistischen Effekt. / In this work the influence of expression and stimulation of the human AT2 receptor on Collagen I alpha 2-mRNA-content and migration of porcine cardiac fibroblastst was tested to clarify the question if AT2 receptors promote AT1 antagonistic antifibrotic and antimigratory effects on collagen I alpha 2-mRNA content and migration. To examine the AT2 receptor function in the cell culture AT2 cDNA was transferred into fibroblasts by adenoviral transduction and the AT2 receptor was overexpressed. Through the use of RT-PCR the relative changes in collagen I alpha 2-mRNA content in TGF-beta1 stimulated and TGF-beta1 plus Ang II stimulated fibroblasts were assayed and compared to the unstimulated control. All values were referred to a reference gene (beta-actin). Stimulation of AT2 receptors did not change the relative collagen I alpha 2-mRNA content of the fibroblasts significantly compared to antisense-(Ad5TA2) transduced fibroblasts. In the modified Boyden-chamber the AT2 mediated effect of Ang II, hPDGF-BB and the combination of both on migration was assessed. The stimulation of AT2 receptors with Ang II inhibited migration compared to nontransduced fibroblasts. In combination with hPDGF-BB Ang II did not change the migration in AT2 overexpressing fibroblasts compared to antisense-(Ad5TA2)-transduced fibroblasts. In the case of exclusive stimulation of AT2-expressing fibroblasts with hPDGF-BB a significantly lower migration was found compared to antisense-(Ad5TA2)-transduced fibroblasts. The underlying therory that AT2 expression and stimulation inhibits the relative collagen I alpha 2-mRNA content could not be confirmed in this work. This did not reveal an inhibitory AT2 mediated effect of Ang II in respect to the TGF-beta1 induced collagen I alpha 2-mRNA content. In contrast to that Ang II stimulation of overexpressed AT2 receptors led to a decreased migration and mediated an AT1 antagonistic effect.

Wound dressing plays an important role in wound recovery and collagen interacts with the human body in such a way that it has specific advantages compared to synthetic materials. The aim of the present study was to get an optimal crosslinking agent for collagen and so the mechanical, chemical and biochemical properties of crosslinked collagen materials were investigated. Fibroblast cells are important in the process of wound healing, so the interaction of human fibroblast cells with crosslinked collagen films were investigated as well. Collagen I was isolated from bovine achilles tendons and collagen films were formed using the isolated collagen I solution. Collagen films were crosslinked with glutaraldehyde (GA), genipin, hexamethylenediisocyanate (HMDC), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) at the equal concentration of 0.02 M and these crosslinked collagen films were compared with uncrosslinked collagen films (control). The surfaces of the crosslinked films were investigated using scanning electron microscopy (SEM). There was observable fibre structure on GA- and genipin-crosslinked collagen films. The tensile strength, elongation at break and low strain modulus of the crosslinked collagen films were investigated. The results showed that GA-, genipin- and HMDC-crosslinked collagen films obtained higher tensile strength than the control. Elongation at break of all the crosslinked collagen films became lower than the control. GA- and genipin-crosslinked collagen films obtained higher low strain modulus than other crosslinked collagen films and the control. The denaturation temperatures of all crosslinked collagen films were significantly higher than the control and the denaturation temperatures of GA- and genipin-crosslinked films were much higher than those of HMDC- and EDC-crosslinked films. All the crosslinked collagen films were resistant to the digestion of collagenase. These results suggest that all the crosslinking agents are effective and GA- and genipin-crosslinked films obtained more extensive crosslinking. The interaction of crosslinked collagen films with fibroblast cells was investigated, e.g. adhesion, proliferation and migration of fibroblast cells. The results demonstrated that the control, genipin- and EDC-crosslinked collagen films were conducive to cell adhesion. Fibroblast cells on the control, genipin- and EDC-crosslinked collagen films were able to proliferate after 24 hours, with increased growth after 48 hours. The fibroblast cells on the control, genipin- and EDC-crosslinked collagen films migrated directionally. The cells on genipin-crosslinked film initiated directional migration earlier than those on control- and EDC-crosslinked films. In summary, genipin crosslinked collagen films show high denaturation temperature, higher tensile strength and good biocompatibility for fibroblast cells adhesion, proliferation and migration. Genipin should be regarded as a suitable crosslinking agent for reconstituted collagen for use in wound dressing.

No description available.