Bossone Research Center, Room 709, located at 32nd and Market Streets.
BIOMED Master's Thesis Defense
Biomimetic Proteoglycan Interactions with Type I Collagen Investigated via 2D and 3D TEM
Carli Moorehead, MS Candidate, School of Biomedical Engineering, Science and Health Systems, and Materials Science and Engineering
Michele Marcolongo, PhD, Department Head and Professor, Materials Science and Engineering
Collagen is one of the leading components in extracellular matrix (ECM), providing durability, structural integrity, and functionality for many tissues. Regulation of collagen fibrillogenesis and degradation is important in the treatment of a number of diseases from orthopedic injuries to genetic deficiencies. Recently, novel, biocompatible, semi-synthetic biomimetic proteoglycans (BPGs) were developed, which consist of an enzymatically resistant synthetic polymer core and natural chondroitin sulfate bristles. It was demonstrated that BPGs affect type I collagen fibrillogenesis, as reflected by their impact delaying the kinetic formation of gels similar to native PGs. This indicates that the structural properties of collagen scaffolds as well as endogenous ECM could also be modulated by these proteoglycan mimics.
However, the imaging modality used previously, reflectance confocal microscopy, did not yield the resolution necessary to spatially localize BPGs within the collagen network or investigate the effect of BPGs on the quality of collagen fibrils produced which is important for understanding the method of interaction. Consequently, a histological technique, electron tomography, was adapted and utilized to 3D image the nano-scale structures within this simplified tissue model. BPGs were found to aid in lateral growth and enhance fibril banding periodicity resulting in structures more closely resembling those in tissue, in addition to attaching to the collagen surface despite the lack of a protein core.