Design and fabrication of a generic 3D-printed silicone unilateral cleft lip and palate model.

The complexity of plastic surgery procedures often requires visualization of the anatomy in three dimensions and therefore demands the development of new and innovative teaching methods. This work describes the development and manufacture of a 3D silicone cleft lip and palate (CLP) model evaluated by surgical residents on its similarity to the biological model. Thirty unilateral CLP models were created and distributed to residents at two different institutions. The model was based on an adult CT scan that was manipulated to resemble an infant with a complete unilateral CLP. This digital model was directly printed in silicone elastomer pieces and later assembled. The residents rated the model based on its realistic value as well as whether or not they felt it improved their surgical technique. Twenty residents used the model to simulate a CLP repair. The structure of the model was rated as fairly realistic while both the material and assembly of the model require improvement in subsequent manufacturing. Post simulation, residents rated the model highly for how accurately it simulated the surgical procedure. An accurate 3D silicone unilateral cleft lip and palate replica was successfully created for educational purposes. This new approach combines a flexible generic design with automated manufacture.

Bio-inspired in situ crosslinking and mineralization of electrospun collagen scaffolds for bone tissue engineering.

Bone disorders are the most common cause of severe long term pain and physical disability, and affect millions of people around the world. In the present study, we report bio-inspired preparation of bone-like composite structures by electrospinning of collagen containing catecholamines and Ca(2+). The presence of divalent cation induces simultaneous partial oxidative polymerization of catecholamines and crosslinking of collagen nanofibers, thus producing mats that are mechanically robust and confer photoluminescence properties. Subsequent mineralization of the mats by ammonium carbonate leads to complete oxidative polymerization of catecholamines and precipitation of amorphous CaCO3. The collagen composite scaffolds display outstanding mechanical properties with Young's modulus approaching the limits of cancellous bone. Biological studies demonstrate that human fetal osteoblasts seeded on to the composite scaffolds display enhanced cell adhesion, penetration, proliferation, differentiation and osteogenic expression of osteocalcin, osteopontin and bone matrix protein when compared to pristine collagen or tissue culture plates. Among the two catecholamines, mats containing norepinephrine displayed superior mechanical, photoluminescence and biological properties than mats loaded with dopamine. These smart multifunctional scaffolds could potentially be utilized to repair and regenerate bone defects and injuries.

Mimicking native extracellular matrix with phytic acid-crosslinked protein nanofibers for cardiac tissue engineering.

A functional scaffold fabricated is developed from natural polymers, favoring regeneration of the ischemic myocardium. Hemoglobin/gelatin/fibrinogen (Hb/gel/fib) nanofibers are fabricated by electrospinning and are characterized for morphology, scaffold composition, functional groups and hydrophilicity. It is hypothesized that ex vivo pretreatment of mesenchymal stem cells (MSCs) using 5-azacytidine and such a functional nanofibrous construct having a high oxygen-carrying potential could lead to enhanced cardiomyogenic differentiation of MSCs and result in superior biological and functional effects. The combination of a functional nanofibrous scaffold composed of natural polymers and crosslinked with a natural crosslinking agent, phytic acid, and stem cell biology may prove to be a novel therapeutic device for treatment of myocardial infarction.