A Polymeric Delivery System Enables Controlled Release of Genipin for Spatially-Confined In Situ Crosslinking of Injured Connective Tissues.

An emerging approach toward repair of connective tissues applies exogenous crosslinkers to mechanically augment injured structures in vivo. One crosslinker that has been explored for this purpose is the plant-derived small molecule genipin. However, genipin's high reactivity to primary amines in proteins, small size, and high diffusion coefficient necessitate localizing and controlling its delivery to avoid off-target or adverse effects.

Elucidating the Structure-Function Relationship of Solvent and Cross-Linker on Affinity-Based Release from Cyclodextrin Hydrogels.

Minocycline (MNC) is a tetracycline antibiotic capable of associating with cyclodextrin (CD), and it is a frontline drug for many instances of implant infection. Due to its broad-spectrum activity and long half-life, MNC represents an ideal drug for localized delivery; however, classic polymer formulations, particularly hydrogels, result in biphasic release less suitable for sustained anti-microbial action. A polymer delivery system capable of sustained, steady drug delivery rates poses an attractive target to maximize the antimicrobial activity of MNC.

Injectable liquid polymers extend the delivery of corticosteroids for the treatment of osteoarthritis.

Drug delivery strategies generally use inert materials, such as high molecular weight polymers, to encapsulate and control the release rate of therapeutic drugs. Diffusion governs release and depends on the ease of permeation of the polymer alongside the device thickness. Yet in applications such as osteoarthritis, the physiological constraints and limited intra-articular joint space prevent the use of large, solid drug delivery implants.

Localized Affinity-Based Delivery of Prinomastat for Cancer Treatment.

Glioblastoma multiforme patients suffer a median survival of 14 months, facilitated by the highly invasive nature of this cancer that allows for it to evade conventional therapy. Prinomastat targets the essential matrix metalloproteinase degradation of the extracellular matrix needed for cancer invasion; however, its clinical potential is impeded by adverse musculoskeletal side effects. By localizing delivery of prinomastat via cyclodextrin polymers, systemic side effects can be bypassed.

Using Affinity To Provide Long-Term Delivery of Antiangiogenic Drugs in Cancer Therapy.

Antiangiogenic drugs encompass many of the different cancer drugs currently under clinical investigation. One of the drawbacks of antiangiogenic therapy, though, is that upon cessation of drug treatment tumors can recur with an accelerated growth rate. In this study we investigate the capacity of using affinity interactions between a polymer made from cyclodextrin and four antiangiogenic drugs, tranilast, SU5416, 2-methoxyestradiol, and silibinin, with the ultimate goal of creating delivery profiles on the order of antiangiogenic processes (needing weeks, rather than hours of delivery).

Local release from affinity-based polymers increases urethral concentration of the stem cell chemokine CCL7 in rats.

The protein chemokine (C-C motif) ligand 7 (CCL7) is significantly over-expressed in urethral and vaginal tissues immediately following vaginal distention in a rat model of stress urinary incontinence. Further evidence, in this scenario and other clinical scenarios, indicates CCL7 stimulates stem cell homing for regenerative repair. This CCL7 gradient is likely absent or compromised in the natural repair process of women who continue to suffer from SUI into advanced age.

Providing sustained transgene induction through affinity-based drug delivery.

Small molecule drug activators of gene expression have been used in applications ranging from gene therapy, to tissue engineering and regenerative medicine. One concern is that for sustained gene expression, a long-term, controlled delivery system is needed. Insoluble polymers containing a high proportion of cyclodextrin (CD) affinity groups have been shown to prolong drug delivery far beyond that capable of polymers relying on diffusion alone.