Bioactive Polyurethane-Poly(ethylene Glycol) Diacrylate Hydrogels for Applications in Tissue Engineering.

Polyurethanes (PUs) are a highly adaptable class of biomaterials that are among some of the most researched materials for various biomedical applications. However, engineered tissue scaffolds composed of PU have not found their way into clinical application, mainly due to the difficulty of balancing the control of material properties with the desired cellular response. A simple method for the synthesis of tunable bioactive poly(ethylene glycol) diacrylate (PEGDA) hydrogels containing photocurable PU is described.

A Study of Wave Confinement and Optical Force in Polydimethlysiloxane-Arylazopyrazole Composite for Photonic Applications.

A refractive index of dielectrics was modified by several methods and was known to have direct influence on optical forces in nanophotonic structures. The present contribution shows that isomerization of photoswitching molecules can be used to regulate refractive index of dielectrics in-situ. In particular, spectroscopic study of a polydimethylsiloxane-arylazopyrazole (PDMS-AAP) composite revealed that refractive index of the composite shifts from 2.

The role of the HBCU pipeline in diversifying the STEM workforce: Training the next generation of drug delivery researchers.

Training the next generation of diverse drug delivery researchers is critical as there is a myriad of challenges that must be solved in the field. HBCUs have been and will continue to remain key factors in training significant numbers of diverse STEM graduates that enter a talented pool of potential drug delivery researchers. Several factors, both structural and psychosocial, play a role in preparing future African American researchers.

Balancing the rates of new bone formation and polymer degradation enhances healing of weight-bearing allograft/polyurethane composites in rabbit femoral defects.

There is a compelling clinical need for bone grafts with initial bone-like mechanical properties that actively remodel for repair of weight-bearing bone defects, such as fractures of the tibial plateau and vertebrae. However, there is a paucity of studies investigating remodeling of weight-bearing bone grafts in preclinical models, and consequently there is limited understanding of the mechanisms by which these grafts remodel in vivo. In this study, we investigated the effects of the rates of new bone formation, matrix resorption, and polymer degradation on healing of settable weight-bearing polyurethane/allograft composites in a rabbit femoral condyle defect model.

Systematic optimization of multiplex zymography protocol to detect active cathepsins K, L, S, and V in healthy and diseased tissue: compromise among limits of detection, reduced time, and resources.

Cysteine cathepsins are a family of proteases identified in cancer, atherosclerosis, osteoporosis, arthritis, and a number of other diseases. As this number continues to rise, so does the need for low cost, broad use quantitative assays to detect their activity and can be translated to the clinic in the hospital or in low resource settings. Multiplex cathepsin zymography is one such assay that detects subnanomolar levels of active cathepsins K, L, S, and V in cell or tissue preparations observed as clear bands of proteolytic activity after gelatin substrate SDS-PAGE with conditions optimal for cathepsin renaturing and activity.

Biocompatibility and chemical reaction kinetics of injectable, settable polyurethane/allograft bone biocomposites.

Injectable and settable bone grafts offer significant advantages over pre-formed implants due to their ability to be administered using minimally invasive techniques and to conform to the shape of the defect. However, injectable biomaterials present biocompatibility challenges due to the potential toxicity and ultimate fate of reactive components that are not incorporated in the final cured product. In this study the effects of stoichiometry and triethylenediamine (TEDA) catalyst concentration on the reactivity, injectability, and biocompatibility of two component lysine-derived polyurethane (PUR) biocomposites were investigated.

Injectable reactive biocomposites for bone healing in critical-size rabbit calvarial defects.

Craniofacial injuries can result from trauma, tumor ablation, or infection and may require multiple surgical revisions. To address the challenges associated with treating craniofacial bone defects, an ideal material should have the ability to fit complex defects (i.e.

Synthesis, characterization of calcium phosphates/polyurethane composites for weight-bearing implants.

Calcium phosphate (CaP)/polymer composites have been studied as an alternative graft material for the treatment of bone defects. In this study, lysine-triisocyanate-based polyurethane (PUR) composites were synthesized from both hydroxyapatite (HA) and β-tricalcium phosphate (TCP) to reduce the brittleness of CaP and increase the bioactivity of the polymer. The mechanical properties and in vitro cellular response were investigated for both HA/PUR and TCP/PUR composites.

Synthesis and characterization of an injectable allograft bone/polymer composite bone void filler with tunable mechanical properties.

In recent years, considerable effort has been expended toward the development of synthetic bone graft materials. Injectable biomaterials offer several advantages relative to implants due to their ability to cure in situ, thus conforming to irregularly shaped defects. While Food and Drug Administration-approved injectable calcium phosphate cements have excellent osteoconductivity and compressive strengths, these materials have small pore sizes (e.

Synthesis, characterization, and remodeling of weight-bearing allograft bone/polyurethane composites in the rabbit.

The process of bone healing requires the restoration of both anatomy and physiology, and there is a recognized need for innovative biomaterials that facilitate remodeling throughout this complex process. While porous scaffolds with a high degree of interconnectivity are known to accelerate cellular infiltration and new bone formation, the presence of pores significantly diminishes the initial mechanical properties of the materials, rendering them largely unsuitable for load-bearing applications. In this study, a family of non-porous composites has been fabricated by reactive compression molding of mineralized allograft bone particles (MBPs) with a biodegradable polyurethane (PUR) binder, which is synthesized from a polyester polyol and a lysine-derived polyisocyanate.

Synthesis, mechanical properties, biocompatibility, and biodegradation of polyurethane networks from lysine polyisocyanates.

Bone defects, such as compressive fractures in the vertebral bodies, are frequently treated with acrylic bone cements (e.g., PMMA).