Bioresponsive lab diagram and imaging

Bioresponsive Materials Lab

Our lab seeks to develop biomaterial and therapeutic delivery systems that specifically respond to cell-generated signals. These next-generation, "smart" material systems enable us to engineer comprehensive regeneration of damaged or diseased tissues.

Overview

Specific applications for these healing-responsive technologies include:

  • Large-scale regeneration of orthopedic injuries or defects
  • Healing of chronic skin wounds
  • Elimination of dental implant infections

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.

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.
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.
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.
Oxidation responsive diagram

Martin JR, Howard MT, Wang S, Berger AG, Hammond PT. Oxidation‐Responsive, Tunable Growth Factor Delivery from Polyelectrolyte‐Coated Implants. Advanced Healthcare Materials 2021, 2001941.

Digram of antioxidant PTK hydrogels for stem cell delivery

Martin JR*, Patil P*, Yu F, Gupta MK, Duvall CL. Enhanced stem cell retention and antioxidative protection with injectable, ROS-degradable PEG hydrogels. Biomaterials 2020. 263: 120377. *Equally contributing authors.

Diagram of wound healing

Patil P*, Martin JR*, Sarett SM, Pollins AC, Cardwell NL, Davidson JM, Guelcher SA, Nanney LB, Duvall CL. Porcine Ischemic Wound Healing Model for Preclinical Testing of Degradable Biomaterials. Tissue Engineering Part C 2017; 23(11): 754 - 762. *Equally contributing authors

Diagram of diabetic wound healing process

Martin JR, Nelson CE, Gupta MK, Yu F, Sarett SM, Hocking KM, Pollins AC, Nanney LB, Davidson JM, Guelcher SA, Duvall CL. Local Delivery of PHD2 siRNA from ROS-Degradable Scaffolds to Promote Diabetic Wound Healing. Advanced Healthcare Materials 2016; 5(21): 2751 – 2757.

Diagram of enhanced would stenting

Martin JR, Gupta MK, Page JM, Yu F, Davidson JM, Guelcher SA, Duvall CL. A Porous Tissue Engineering Scaffold Selectively Degraded by Cell-Generated Reactive Oxygen Species. Biomaterials 2014; 35(12): 3766 – 3776

Additional Publications

We are currently seeking talented and motivated students from a broad range of disciplines - apply today!


Graduate Students

Potential graduate students (both Masters and Doctoral) should contact Dr. Martin by email and can apply for admission through the University of Cincinnati online portal.

Undergraduate Students

Undergraduates interested in research opportunities should contact Dr. Martin by email. We are prepared to host students from all levels of prior experience and from a diverse background of majors, including engineering, materials science, biology, physics, and chemistry.


Contact Us

The Bioresponsive Materials Lab is located in room 549 in the Engineering Research Center (ERC) at the University of Cincinnati in Cincinnati, OH.

Address:
828 Engineering Research Center
2901 Woodside Dr
Cincinnati, OH 45221

Follow us on Twitter! @MartinLab_UC

Director & Principal Investigator

Headshot of John Robert Martin

John Robert Martin

Assistant Professor, CEAS - Biomedical Eng

134 UCBIOSCI

513-556-6548

John R. Martin is an assistant professor in the Department of Biomedical Engineering in the College of Engineering and Applied Science at the University of Cincinnati. Dr. Martin completed his undergraduate degree at the University of Kentucky where he majored in Biosystems Engineering before obtaining a Ph.D. in Biomedical Engineering at Vanderbilt University investigating cell-degradable tissue engineering scaffolds. Following his doctoral work, he completed a postdoctoral fellowship at the Massachusetts Institute of Technology in the Department of Chemical Engineering where he researched drug delivery systems for the regeneration of craniofacial bone tissue.
 
Dr. Martin leads the Bioresponsive Materials Lab at UC, exploring “smart” biomaterial systems that leverage precise cell-generated signals (including reactive oxygen species and enzymatic activity) to activate biomaterial functionality and guide tissue regeneration. This interdisciplinary research integrates polymer science and materials engineering alongside pharmacology and biology to build new systems for regenerating orthopedic injuries in the clinic.

Graduate Students

Headshot of Karina Bruce, B.S.

Karina Bruce, B.S.

Karina Bruce is a first year Ph.D. student developing inflammation-responsive antibiotic coatings to combat bacterial infections in bone fractures.

Headshot of Dylan Marques, B.S.

Dylan Marques, B.S.

Dylan Marques is a second year Ph.D. student working towards a dual phase drug delivery system for regenerating cranial defects.

Headshot of Reinaldo Dos Santos, B.S.

Reinaldo Dos Santos, B.S.

Reinaldo Dos Santos is a second year Ph.D. student developing cell-degradable tissue engineering materials for regenerating bone defects and improving fracture fixation.

Undergraduate Students

Headshot of Andrew Hoffmann

Andrew Hoffmann

Andrew Hoffmann is a fifth year Biomedical Engineering undergraduate student in Research Co-op/Capstone and is developing new bioresponsive drug coatings.

Headshot of Nick Hughes

Nick Hughes

Nick Hughes is a fourth year Biomedical Engineering undergraduate student in Research Co-op and is developing calcium-scavenging hydrogels.

Headshot of Andrea Frankel

Andrea Frankel

Andrea Frankel is a fifth year Biomedical Engineering undergraduate and part-time researcher/Research Capstone student. She is developing drug coatings to prevent bone graft resorption.

Headshot of Adolphus Addison

Adolphus Addison

Adolphus Addison is a second year Biomedical Engineering undergraduate student and a 2023 Protégé Scholar. He is developing new moldable bone cement formulations.

Lab Alumni