Polycaprolactone Thin-Film Micro- and Nanoporous Cell-Encapsulation Devices.

Cell-encapsulating devices can play an important role in advancing the types of tissue available for transplantation and further improving transplant success rates. To have an effective device, encapsulated cells must remain viable, respond to external stimulus, and be protected from immune responses, and the device itself must elicit a minimal foreign body response. To address these challenges, we developed a micro- and a nanoporous thin-film cell encapsulation device from polycaprolactone (PCL), a material previously used in FDA-approved biomedical devices.

Compliant 3D microenvironment improves β-cell cluster insulin expression through mechanosensing and β-catenin signaling.

Type 1 diabetes is chronic disease with numerous complications and currently no cure. Tissue engineering strategies have shown promise in providing a therapeutic solution, but maintenance of islet function and survival within these therapies represents a formidable challenge. The islet microenvironment may hold the key for proper islet maintenance.

Membranes to achieve immunoprotection of transplanted islets.

Transplantation of islet or beta cells is seen as the cure for type 1 diabetes since it allows physiological regulation of blood glucose levels without requiring any compliance from the patients. In order to circumvent the use of immunosuppressive drugs (and their side effects), semipermeable membranes have been developed to encapsulate and immunoprotect transplanted cells. This review presents the historical developments of immunoisolation and provides an update on the current research in this field.

Size-controlled insulin-secreting cell clusters.

The search for an effective cure for type I diabetes from the transplantation of encapsulated pancreatic β-cell clusters has so far produced sub-optimal clinical outcomes. Previous efforts have not controlled the size of transplanted clusters, a parameter implicated in affecting long-term viability and the secretion of therapeutically sufficient insulin. Here we demonstrate a method based on covalent attachment of patterned laminin for fabricating uniformly size-controlled insulin-secreting cell clusters.

Ruthenium nitrosyls derived from tetradentate ligands containing carboxamido-N and phenolato-o donors: syntheses, structures, photolability, and time dependent density functional theory studies.

In order to examine the role(s) of designed ligands on the NO photolability of {Ru-NO}(6) nitrosyls, a set of three nitrosyls with ligands containing two carboxamide groups along with a varying number of phenolates have been synthesized. The nitrosyls namely, (NEt(4))(2)[(hybeb)Ru(NO)(OEt)] (1), (PPh(4))[(hypyb)Ru(NO)(OEt)] (2), and [(bpb)Ru(NO)(OEt)] (3) have been characterized by X-ray crystallography. Complexes 1-3 are diamagnetic, exhibit nu(NO) in the range 1780-1840 cm(-1) and rapidly release NO in solution upon exposure to low power UV light (7 mW/cm(2)).

Facile ligand oxidation and ring nitration in ruthenium complexes derived from a ligand with dicarboxamide-N and phosphine-P donors.

The reaction of the tetradentate dicarboxamide ligand 1,2-bis-N-[2'(diphenylphosphanyl)benzoyl]diaminobenzene (dppbH(2)) with RuCl(3) in DMF or ethanol results in metal-mediated ligand oxidation and formation of the diamagnetic Ru(II) complex [(dppQ)Ru(Cl)(2)] (1) with N(2)P(2) chromophore. The o-phenylenedicarboxamide portion of the dppb(2-) ligand is oxidized to a o-benzoquinonediimine (bqdi) moiety in [(dppQ)Ru(Cl)(2)]. Presence of oxygen accelerates the ligand oxidation process.