Biomaterials REU - University of California, San Diego
Program Directors

  Adam J Engler, Ph.D.
"Heart Attack-in-a-dish"
This project will involve students developing new materials that stiffen with time to mimic the remodeling that occurs with heart disease. Participants will also use cutting edge genetic tools to create and use patient-derived stem cells to create heart cells. Patients with specific mutations will be studied within the biomaterial to determine what effects the stiffened environment has on mutant and wild-type cells.
   
  Roberto Gaetani, Ph.D.
   
  Program Faculty
 
Adah Almutairi, PhD

Smart Polymers for Drug Delivery Systems
The Almutairi lab's interests lie two main areas. The first is in the design of responsive polymeric systems that degrade when triggered to deliver therapeutics. Our smart polymers degrade in response to light and reactive oxygen species. The second is in synthesis of upconverting nanoparticles for imaging.
 
Shaochen Chen, PhD

3D Printed Heart Chambers
The project will train the REU students for cutting-edge research in 3D bioprinting using advanced biomaterials. REU Participants will work on one on-going project to 3D print cardiomyocytes into a dual chambered system with fluid pumping capabilities similar to the human heart as a first step towards making a tissue engineered heart. The Participants will work alongside Dr. Chen and their Research Mentors to identify the materials and printing methods to be used, but utilizing our strengths in digitally printed hydrogels using acrylamide, polyethelyne glycol, glycosaminoglycans, and other polymers. The Participant will identify crosslinking methods and other parameters and fabricated a heart chamber capable of directed fluid motion using digital plasmonic printing. Chambers will be modeled in Matlab to ensure appropriate fluid motion.
 
Shu Chien, MD, PhD

Material Cues for Stem Cell Fate
The project will train the REU students for cutting-edge research in rapid 3D bioprinting using advanced hydrogel biomaterials. The REU students will work on on-going projects to 3D print in vitro tissue-in-a-dish (e.g. liver, heart, or brain) using iPSCs. The REU student will work alongside Dr. Chien, Dr. Shaochen Chen, and the mentors to optimize the biomaterials and 3D printing parameters. We will analyze the mechanical and physical properties of the hydrogel scaffolds, and characterize the biological functions of the precision tissue models. These 3D human tissue models are finding their applications in disease modeling and early drug screening.
 
Karen Christman, PhD

Nano-aggregation strategies for the Heart
There is a significant need to better deliver drugs to the heart after myocardial infarction. Nanoparticle delivery strategies are particularly attractive since they can be delivered via leaky vasculature created by the myocardial infarct. We have developed nanoparticles that aggregate after matrix metalloproteinase cleavage of an external protective layer. These aggregates remain at the infarction site for at least one month, and so we hypothesize that nanoparticle aggregates will significantly improve the yield and sustained release of drugs that minimize post-MI remodeling. The first REU Participant will learn the polymer synthesis, nanoparticle fabrication, and drug loading. He/she will perform in vitro assays to assess drug release and activity for FDA-approved drugs. Subsequent Participants will additionally alter how drugs are loaded (surface erosion versus diffusion) to change delivery kinetics to establish dosing amount, duration, and rate.
 
Stephanie I. Fraley, PhD

Collagen Biomaterials as Tools for Tissue Engineering
A major challenge to using fibrillar collagen as an engineered scaffold is the limited reproducibility of gelation, which impacts cellular functions. Gelation temperature and pH impact porosity, fiber diameter and alignment, and mechanical properties, thus we propose developing a microfluidic 3D collagen hydrogel curing system to generate defined extracellular matrix (ECM) fiber architectures in high throughput with precise thermal and pH modulation of the gelation process. The REU Participant will work with a graduate student Research Mentor to design the microfluidic curing system. The Participant will use COMSOL software to model the system and optimize the design prior to prototyping. The resulting tightly-controlled gelation system will enable highly mechanistic studies of cell-ECM interactions using a native protein hydrogel and create a platform for high-throughput optimization of ECM architecture to better define the cues needed to improve tissue engineering. In the process, the Participant will also learn cutting edge microscopy methods, including reflection confocal imaging and electron microscopy.
 
Ester Kwon, PhD

Nanoscale delivery for traumatic brain injury
Drug delivery to the brain remains a challenge, in particular the delivery of biomolecules such as proteins and nucleic acids. Design of nanoscale materials may offer a strategy to improve access of therapeutics to injured brain tissue. The goal of this REU is to engineer a nanomaterial that can interact with injured brain tissue and deliver therapeutics. In this project, the participant will synthesize nanomaterials, characterize nanomaterials, and evaluate interaction of nanomaterials with living cells. The REU will work directly with Dr. Kwon and a mentor to develop an individual training plan, learn experimental techniques, and communicate research findings.
 
Prashant Mali, PhD

Systematic study and engineering of pancreatic organogenesis
We will utilize and develop a vascularized bioprinting platform in the laboratory to build and mature pancreatic tissues ex vivo. Incorporating constituent cells generated via pluripotent stem cell differentiation, and via systematic evaluation of biomaterials, media, and local cellular microenvironment modulations we will aim to build functional and mature pancreatic tissue constructs. We will utilize omic, histology, and in vivo transplantation studies in SPZ-induced diabetic mice to assess for structure, function, and maturity of thus engineered organotypic tissues. In the process, researchers are anticipated to learn skills in tissue engineering, synthetic biology, cell culture, and animal handling procedures.
 
Joanna McKittrick, PhD

Collagen Biomaterials as Tools for Tissue Engineering
Robust and biocompatible bone implants are needed, and we have shown that bone micro-structures of lower vertebrates offer superior deformability. We hypothesize that ceramic scaffolds formed by an ice templating method will mimic the same structural and mechanical properties of bones from lower vertebrates, facilitate cell infiltration, and can be incorporated into human bone defects. The REU Participant will fabricate bone implant materials and evaluate them by performing mechanical and cell adhesion tests. The Participant will fabricate ceramic scaffolds using an ice templating method and infiltrate the scaffolds with a biopolymer. The composites will be tested in compression and evaluated for osteoblast adhesion. The Participant, in conjunction with Research Mentors, will perform statistical analysis on all tests, determine the processing conditions that optimize the potential bone implant, and compare that to native bone to assess the success of our hypothesis.
 
Robert L. Sah, MD, ScD

Osteochondral Implants for Resurfacing Osteoarthritic Joints
Osteochondral grafts are effective for repairing large areas of damaged cartilage but are limited by donor availability. Organ-scale bioreactors have the potential to rapidly generate osteochondral implants, increasing implant supply and addressing advanced disease including osteoarthritis. The REU participant will work with Prof. Sah and advanced researchers to create and test such bioreactors, and assess suitability of the osteochondral implant for in vivo application, based on experimental analyses of biomechanical and biological properties. The participant will learn to conduct studies using advanced methods in bioreactors and biomechanics.
 
Michael Sailor, PhD

Porous Silicon Nanoparticles for In Vivo Imaging and Delivery of Biologic Therapeutics
Porous silicon nanoparticles (PSiNPs) are a new class of quantum dots that are non-toxic, biodegradable, and that can be readily imaged in vivo. Due to their highly porous nature, the materials can secure and effectively deliver a range of protein- and nucleic acid-based therapeutics. REU Participants will explore the fundamental properties of these nanomaterials, focused on the following topical areas: in vivo imaging, next-generation nanofiber scaffolds for spinal cord and other neuronal injuries, nanotherapies for treatment of resistant bacterial infections, and gene delivery. As part of their training, the REU student will participate in the UCSD Summer School for Silicon Nanotechnology (http://sailorgroup.ucsd.edu/courses/SummerSchool/).
 
Liangfang Zhang, PhD

Cell-membrane-coated Nanoparticles
Most biomaterials fail to efficiently target and deliver cancer drugs because they are recognized as foreign to the body before they can deliver their payload. We hypothesize that a cell membrane coating around our nanoparticle systems could mask them from the immune system to prolong their circulation and act as a platform for targeting via transmembrane proteins. REU Participants will be directly involved in this research project by first working alongside Dr. Zhang and a senior graduate student to learn how to synthesize and characterize the proposed cell membrane coated nanoparticles. Then each REU Participant will be assigned to a project team that is attempting to incorporate specific integral membrane proteins for targeting, to synthesize nanoparticles at various formulation parameters, or to optimize large-scale nanoparticle fabrication. Each of these projects collectively will contribute to the completion of the overall research goal of Dr. Zhang’s lab.