David L Kaplan

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Silk from the silkworm, Bombyx mori, has been used as biomedical suture material for centuries. The unique mechanical properties of these fibers provided important clinical repair options for many applications. During the past 20 years, some biocompatibility problems have been reported for silkworm silk; however, contamination from residual sericin(More)
The Trp53 gene family member Trp73 encodes two major groups of protein isoforms, TAp73 and DeltaNp73, with opposing pro- and anti-apoptotic functions; consequently, their relative ratio regulates cell fate. However, the precise roles of p73 isoforms in cellular events such as tumor initiation, embryonic development, and cell death remain unclear. To(More)
Silk fibroin fiber scaffolds containing bone morphogenetic protein 2 (BMP-2) and/or nanoparticles of hydroxyapatite (nHAP) prepared via electrospinning were used for in vitro bone formation from human bone marrow-derived mesenchymal stem cells (hMSCs). BMP-2 survived the aqueous-based electrospinnig process in bioactive form. hMSCs were cultured for up to(More)
The villi of the human and chick gut are formed in similar stepwise progressions, wherein the mesenchyme and attached epithelium first fold into longitudinal ridges, then a zigzag pattern, and lastly individual villi. We find that these steps of villification depend on the sequential differentiation of the distinct smooth muscle layers of the gut, which(More)
A silk-fiber matrix was studied as a suitable material for tissue engineering anterior cruciate ligaments (ACL). The matrix was successfully designed to match the complex and demanding mechanical requirements of a native human ACL, including adequate fatigue performance. This protein matrix supported the attachment, expansion and differentiation of adult(More)
We report studies of bone tissue engineering using human mesenchymal stem cells (MSCs), a protein substrate (film or scaffold; fast degrading unmodified collagen, or slowly degrading cross-linked collagen and silk), and a bioreactor (static culture, spinner flask, or perfused cartridge). MSCs were isolated from human bone marrow, characterized for the(More)
Spider dragline silk is a remarkably strong fiber that makes it attractive for numerous applications. Much has thus been done to make similar fibers by biomimic spinning of recombinant dragline silk proteins. However, success is limited in part due to the inability to successfully express native-sized recombinant silk proteins (250-320 kDa). Here we show(More)
Growth factors, hormones, and other regulatory molecules are traditionally required in tissue engineering studies to direct the differentiation of progenitor cells along specific lineages. We demonstrate that mechanical stimulation in vitro, without ligament-selective exogenous growth and differentiation factors, induces the differentiation of mesenchymal(More)