A multi-enzyme-mimicking bioceramic material for enhanced cell functions

Part 1: Non-technical Summary

When the body processes food and reacts to environmental and other pressures, cells in the body produce free radicals. If the body cannot process and remove free radicals efficiently, oxidative stress can form and become harmful to cells and body function, which has been linked to osteoporosis, osteoarthritis, stroke, cancer, and other inflammatory diseases.

To maintain and boost overall health, neutralizing free radicals in the body is crucial. Antioxidants are thought to have the function to prevent or slow damage to cells by neutralizing free radicals. Green vegetables, fruits, herbs contain many antioxidants, for examples, vitamins, polyphenols, and also various biological enzymes.

However, these natural antioxidants produced from vegetables, fruits or plants have many limitations, such as complicated preparation procedures, unstable reactivity, and environmental sensitivity. Therefore, new artificial antioxidants or enzymes are being studied, for example, synthetic manganese dioxide particles. Manganese is a trace element in the body, and also an essential element for bone health.

The objective of this project is to study whether or not manganese dioxide particles have similar cell-protective functions to those natural enzymes. In this project, manganese dioxide particles are mixed with ceramic particles to form a sponge-like block using a mold, and bone cells are used to test the cell-protective function of the sponge-like blocks.

The project is also to test if the cell-protective function of the manganese dioxide particles can be kept when their structures change from solid into hollow. The instructional objective of this project is to broaden participation in science, technology, engineering and mathematics (STEM) by recruiting middle-high school students and undergraduate students, including those from underrepresented groups, to participate in the research tasks of this effort, and thereby enhance the STEM pipeline.

Part 2: Technical Summary

Inorganic nanoparticles doping into bioceramics for enhanced biomedical function have been widely reported. However, doping manganese dioxide nanoparticles, a mimetic nanozyme, into a calcium phosphate (CaP) ceramic to develop a new biomaterial has not been studied yet. Whether or not the doping of manganese dioxide into CaP bioceramics can still retain the unique enzyme-mimicking function of manganese dioxide while simultaneously enhancing the properties of the CaP biomaterial remains unknown.

Therefore, the primary objective of this project is to investigate whether the doping of manganese dioxide nanoparticles can endow the new cell protective and proliferative functions of a traditional CaP biomaterial while retaining the multi-enzyme-mimicking activities of manganese dioxide nanoparticles. To this end, manganese dioxide nanoparticles with shell/core hollow structures are prepared and doped into a CaP porous scaffold.

The in vitro enzyme-mimetic catalytic activities of the composite porous scaffolds and related mechanisms are investigated. The cell protection function of the new biomaterial is characterized by culturing human bone marrow-derived mesenchymal stem cells on the porous manganese dioxide-doped CaP scaffold. This project fills the gap of the knowledge of whether the doping of manganese dioxide in a ceramic biomaterial scaffold can endow new enzyme-mimicking activities and cell protection/proliferation function for the traditional CaP biomaterial.

This research provides a new platform for the PI to attract and mentor diverse high school students from Florida Atlantic University High School and undergraduate students from Florida Atlantic University, a Hispanic Serving Institution, in project-based summer activities for the next-generation of biomaterial scientists. Educational and outreach plans including teaching courses, conferences, publications, are designed to broaden public awareness of the fundamental knowledge about the cell protective function of nanoparticles-doped ceramic biomaterials.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.