While immunoregulatory therapies hold great promise for the treatment of T1D, their inadequacy and serious toxicity have limited research efforts to find a lifelong immunosuppression approach. This has motivated investigators to search for alternative approaches such as the use of nanotechnology to deliver a wide variety of drugs and biomolecules. In recent years, there have been major strides to address various obstacles in order to bring nanotechnology closer to clinical practice. Nanotechnology has been moving forward on two fronts: 1) synthesis of a NP which efficiently loads, retains and releases drugs and 2) development of an innovative strategy to deliver NP to specific sites. Much progress has been made on NP surface properties and size to reduce burst release, blood opsonization and clearance to enhance the circulation half-life of NP from several minutes to tens of hours.
On the front of delivering NPs to specific tissue sites, we have witnessed less progress. To make our nano-delivery approach applicable to Type 1 diabetes (T1D), we (Abdi and Cheng) have made major strides as follows: (A) we have successfully designed nanomedicines with the desired surface properties and controlled particle sizes to improve their pharmacokinetics, (B) demonstrated that loading and controlled release of the drug is markedly improved by developing a polylactide-drug conjugated nanoparticle, or nanoconjugate, via drug-initiated polymerization of lactide followed by nanoprecipitation, (C) our published data indicate that our nanotechnology platform is highly efficient in delivering immunosuppressive drugs, and importantly..
(D) Importantly, our preliminary data indicate selective PNAd dependent delivery of the nanoparticles to the pancreas and pancreatic lymph nodes in NOD mice. We are interested in examining the expression of PNAd in pancreatic lymph nodes (PLN), pancreas, non draining LN and spleen by immunhistolgoy to assess the feasibility and potential success of our targeted therapy in humans.