Bioresponsive Materials Lab Research

The Bioresponsive Materials Lab seeks to develop new technologies for orchestrating regeneration of diseased or damaged tissues. Current regenerative systems primarily rely on 1) material implants whose biodegradation rates can drastically diverge from the pace of new tissue formation, and 2) poorly controlled pharmaceutic delivery that incompletely recapitulate natural healing processes. Consequently, there remains a need for regenerative medicine platforms that can selectively release therapeutics and biodegrade in response to localized, cell-specific healing responses.

Therefore, our group explores bioresponsive, "smart" material systems that leverage precise, cell-generated signals (including presence of reactive oxygen species, pH changes, and enzymatic activity) to activate biomaterial functionality and guide tissue regeneration.

Orthopedic tissue engineering with cell-degradable scaffolds

Diagram of injectable scaffold delivery into skull
  • Critically-sized bone defects are conventionally treated with patient-derived bone grafts; as such, "off-the-shelf" bone replacement therapies would improve patient quality of life and reduce healthcare costs.
  • Though newer composites with inorganic ceramics and biodegradable synthetic polymers have shown promise as osteoinductive scaffolds, many conventional polyester-based systems are prone to autocatalytic degradation and premature implant failure in preclinical testing.
  • To combat the disconnect between bone regeneration rates and scaffold degradation kinetics, our lab will seek to develop a cell-degradable bone substitute.
  • A specifically cell-degradable implant will marry implant resorption with healing kinetics, thus preventing premature implant failure and improving bone regeneration outcomes.

Multi-stage, healing-responsive drug delivery

Diagram of drug encapsulation
  • Most localized drug delivery platforms focus on the sustained delivery of a single therapeutic agent, while natural regeneration cascades feature a multitude of sequential or overlapping signalling pathways.
  • Drug delivery systems featuring layer-by-layer (LbL) coatings demonstrate precise control over the timing and dosing of therapeutic delivery; however, LbL films have been typically been constrained to coatings on pre-formed implants.
  • This work will seek to develop injectable, cell-degradable microparticles coated with cell-degradable LbL constructs, thereby combining the tunability of LbL drug delivery with the minimally-invasive delivery of microparticles.
  • These microparticle / LbL systems will be able to facilitate locally-responsive, multi-stage delivery of therapeutics via an injectable format.

On-demand antibiotic delivery from dental implants

Diagram of dental implants
  • Dental implants are highly susceptible to bacterial colonization and are conventionally treated by systemic antibiotics (with ensuing off-target effects).
  • Our initial goal is to explore the local tissue environment surrounding infected dental implants to identify infection-specific hallmarks such as bacterial toxins, pH changes, oxidative stress, etc.
  • After identifying suitable targets, efforts will focus on creating layer-by-layer drug coatings on the surfaces of implants that selectively release antibiotics in response to infection-specific stimuli.
  • Responsive antibiotic-releasing drug coatings will drastically extend payload delivery timelines and could serve as a prophylactic for infection prevention.