wonmuk hwang texas a&m engineering experiment station researcher and associate professor in texas a&m universitys department of biomedical engineering is shedding light on how collagen grows at the molecular level and helps form a diverse set of structures in the body ranging from bone tendon blood vessels skin heart and even corneas employing a computational model as well as a newly developed computer program has been able to distinguish molecular-level differences in complex collagen networks formed under different conditions his findings are featured as the cover story for the scientific journal physical review letters collagen while popularly known for its cosmetic uses is the most abundant protein in the human body as the main structural protein in connective tissues it is found in tendons ligaments and skin its also abundant in corneas cartilage bones blood vessels and teeth hwangs research is investigating how collagen forms such a diverse range of materials specifically hes examining how collagen fibrils assemble into ordered networks on surfaces the surface assembly of collagen he says is particularly relevant to biomedical engineers who are looking to use collagen-based coatings on implantable medical devices in order to prevent the devices from being rejected by the bodys immune system we are comparing the differences in collagen-formed structures hwang said what are the real differences between these molecules from different parts of the body what differences exists in collagen that has formed bone and collagen that has formed the cornea if you study this at the molecular level you can begin to see the differences our research aims at providing a quantitative detailed analysis of these differences as part of his research hwang found that collagen fibrils assemble into an intricate network of triangular shapes in which larger shapes are filled with smaller ones iteratively this type of structured network is characterized by scientists as fractal he explained fractal patterns he says arent unique to collagen; in fact they occur throughout nature such as in river networks clouds seashore lines and mountains similar networks even occur among the light-carrying nanofibers of optical-based electronics to explain this widely observed phenomena hwang developed a theory and computational model for the network formation process that allowed him to accurately predict and simulate the growth process hwang tested his models against actual collagen networks with the aid of a computer program he developed known as cafe or computer-aided feature extraction cafe can recognize individual fibrils in images of complex collagen networks hwang explains by combining both the model and cafe it is possible hwang says to precisely distinguish different networks formed under slightly different experimental conditions similar to distinguishing between two paintings that may look alike but have subtle differences thats an important milestone in scientists efforts to understand collagen and its versatility with this program [cafe] we can measure filament lengths and orientations in a complex image hwang explained this is important because once we have this quantitative information we can have a direct comparison with simulations we can simulate a network with the parameters and qualities of a real collagen network when it comes to collagen formation we need to understand what happens at the molecular level and we need to be able to do this in a measurable way quantitatively to better understand how collagen grows and differentiates the guided framework that has resulted from both this theory of collagen growth as well as the validation of our simulations provided by the cafe program is helping achieve this goal