Implantable Nanochannel System for the Controlled Delivery of Osteogenic Growth Peptide
Abstract
Topic Area: The proposed research is submitted under the Fiscal Year 2017 Peer Reviewed Medical Research Program of (1) Nanomaterials for Bone Regeneration and (2) Sustained-Release Drug Delivery. The areas of encouragement include: (a) research on nanomaterial-based methods to facilitate recruitment of endogenous cell populations for enhanced bone regeneration and osseointegration, (b) technologies addressing segmental/large bone defects in craniomaxillofacial and/or load-bearing regions, (c) development of controlled release/extended release of growth factors for bone regeneration, and (d) development of technology that can provide a sustained-release delivery of drugs for a minimum of 1 week or more. Critical Problem: Spinal injuries are among the most disabling conditions affecting wounded members of the U.S. military, and there is a need to improve future outcomes for those with spinal injuries. Spinal fusion is a common surgical procedure used to treat fractures and to heal or “fuse” multiple bone fragments together to create one solid bone. We propose the development of an innovative delivery system, analogous of an hourglass, for the sustained and local delivery of drugs for stimulating bone growth and regeneration to treat skeletal injuries or defects with minimally invasive intervention. Innovation: An hourglass is capable of accurately measuring time by physically restricting the sand inside through a narrow neck. Only a few grains of sand can pass at a time in a constant manner from one bulb to another. Similarly to an hourglass, we propose to use physical confinement to create a system that allows for sustained and constant release of drug molecules, specifically a peptide known to play an important role in bone growth, osteogenic growth peptide (OGP). Constant release of OGP is achieved as it travels from a drug reservoir through nanochannels. These are similar to the narrow neck of an hourglass, but 30,000 times smaller than the thickness of human hair. OGP then is released through an outlet port to nearby tissue and bone in the body. The height of the nanochannels can be modified so that OGP release occurs continuously, in small amounts over the desired time range (months to years). Fabricating our device in this way provides three major advantages: (1) the ability to stimulate new bone growth near a defect site, (2) the capacity to continuously delivery this bone stimulus over an extended period of time, and (3) sustained-release of the drug without any moving components or actuation. Applicability: OGP is already found in the human body circulating in the blood, and it is known to play an important role in bone growth and the production of blood cells and platelets. The device is composed of implantable medical-grade plastic (polyether ether ketone, PEEK). Devices fabricated from PEEK are biocompatible and ensure some flexibility. PEEK has been used as a biomaterial in devices due to its demonstrated resistance to degradation and wear debris. The bio-inert material is also compatible with several different sterilization methods, which aid in preventing infection. We proposed placement of the device along the spine to generate bone growth as a model for spinal fusion. Further, the spine provides two major roles of mobility and weight bearing. Therefore, this device placement was strategically chosen for our studies because the technology will initiate new bone growth from a site of existing bone, tackle a large target area, and address a load-bearing region of the body where strong bone is critical. The target area is sufficiently large that our device design contains two identical membranes, each attached to a drug reservoir. A divider inside the reservoir ensures a balanced release over the target area. The whole device spans the vertebrae vertically along one side of the spine. In this way, we can use the other side of the spine of the same animal as a control. We propose
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 29, 2018
- Source ID
- W81XWH1810438
Entities
People
- Carly S Filgueira
Organizations
- Houston Methodist Research Institute
- United States Army