Seed grant enables researchers to try new approach to targeting leukemia
Thursday, November 3, 2016
University researchers hope to improve the odds of surviving acute myeloid leukemia (AML) with a promising drug that traces its lineage to a chemical found in magnolias. They will load the drug into nanoparticles that will target the inner recesses of bone marrow where leukemia stem cells lurk.
Team members Rudi Fasan, associate professor of chemistry; Danielle Benoit, associate professor of biomedical engineering; and Benjamin Frisch, research assistant professor of hematology and oncology, are supported by a $75,000 University Research Award. The award program is one of several University “seed grants” that help investigators develop preliminary data and proof of concept for promising projects, in hopes of leveraging larger awards from federal agencies or foundations to carry the projects to fruition.
Benoit’s lab, in the meantime, has been developing polymer nanoparticles as vehicles for delivering chemotherapeutic drugs to specific parts of the body where a disease occurs, in order to minimize damage to healthy tissues.
Her lab recently augmented the nanoparticles with a peptide that can help steer the drug vehicles specifically to bone marrow. The peptide binds to the TRAP enzyme that is released when diseased or worn bone tissue is broken down by osteoclasts during the body’s ongoing process of bone remodeling. The remodeling activity is especially prevalent in the marrow of leukemia patients.
Preliminary studies show that the nanoparticles accumulate at a significantly higher rate in TRAP-positive bone tissue than other tissues, and can efficiently load and then gradually release a chemical compound similar to the one Fasan’s lab has developed.
Benoit’s lab will further test how the nanoparticles perform when loaded with analogs of Fasan’s compound, and adjust the nanoparticles accordingly.Read More: Seed grant enables researchers to try new approach to targeting leukemia
Professor Benoit co-PI on NIH funded project: “Salivary gland-specific radio protection”
Tuesday, September 27, 2016
In collaboration with Associate Professor Catherine Ovitt of the Department of Biomedical Genetics, Professor Danielle Benoit is the co-PI on the recently funded NIH research project: “Salivary gland-specific radioprotection.” Briefly, salivary glands are extremely sensitive to ionizing radiation (IR) used as a curative treatment for head and neck cancers. However, mechanisms governing radiation-damage induced losses in salivary gland function is unknown. Therefore, this work focuses on fundamental understanding of salivary gland radiosensitivity and development of therapeutic approaches to protect against damage. If successful these approaches will lend themselves to translation and the development of novel therapy strategies that would improve the quality of life for survivors of head and neck cancer.
Maureen Newman of the Benoit Lab was selected to receive a CMSR Symposium Distinguished Abstract Award
Monday, September 26, 2016
Graduate student Maureen Newman of the Benoit Lab was selected to receive a CMSR Symposium Distinguished Abstract Award this year. This new award recognizes outstanding abstracts that were submitted for the 2016 poster session. Below is her winning abstract:
Nearly 6 million bone fractures occur annually in the United States, with nearly 20% resulting in nonunions or delayed unions . To noninvasively reinitiate fracture healing, small-molecule bone anabolic drugs such as statins and Wnt/β-catenin signaling agonists could be used . However, accumulation of systemically administered small-molecule drugs in bone is <1%. Therefore, to selectively enhance bone regeneration at fractures while reducing overall drug dose and propensity for off-target effects, bone biodistribution must be improved. To achieve bone selectivity, we identified a peptide, tartrate-resistant acid phosphatase (TRAP)-binding peptide (TBP), that has high affinity to TRAP, an enzyme deposited by osteoclasts during the resorption phase of bone remodeling . Incorporating peptide into polymers, such as bioinert and hydrophilic poly(ethylene glycol) (PEG), can increase bone biodistribution of small-molecule drug-polymer conjugates . In this work, we investigated how the spatial orientation of TBP incorporation and polymer molecular weight affect polymer affinity to TRAP and biodistribution to fractures. Two schemes were used to form TBP-functionalized polymers: a one-step reaction using methacrylamidyl-TBP copolymerized with PEG methacrylate, and a two-step reaction using PEG methacrylate copolymerized with methacrylic-xanthate monomer that was subsequently functionalized with TBP. To achieve control over polymer properties, reversible addition-fragmentation chain transfer (RAFT) polymerization was used. Consistent with RAFT, resulting polymers exhibited low polydispersities (≤1.1) and well controlled molecular weights of 20-100 kDa. Molecular weight increased non-linearly over time for one-step reactions due to high initial peptide incorporation. Conversely, molecular weight evolution for two-step reactions was uniform due to similar monomer reactivity. Thus, one-step reactions resulted in peptide gradients, and following peptide conjugation, two-step reactions resulted in random peptide arrangements. To determine if these different polymer architectures affect TRAP affinity, gradient and random copolymers were analyzed using surface plasmon resonance spectroscopy. Both polymer architectures exhibited 1-2 magnitudes greater affinity to TRAP than TBP peptide, but there were no differences in affinity between gradient and random peptide arrangements. Controls of unfunctionalized and scrambled control peptide (SCP)-functionalized polymers showed negligible affinity to TRAP. To further investigate how polymer properties affect TRAP affinity and bone biodistribution, gradient polymers exhibiting similar peptide incorporation in a range of molecular weights (10, 20, 65 kDa) were injected systemically into mice with tibia fractures. Interestingly, 20 kDa polymers exhibited greater apparent TRAP affinity and bone biodistribution compared to 10 kDa and 65 kDa polymers, which localized predominantly to kidney and liver, respectively, indicating a dependence of bone biodistribution on both affinity and molecular weight. Future work will focus on conjugating bone regenerative drugs into targeted polymers to enhance fracture localization and overall healing.
Eva Hansen receives prestigious scholarship from Astronaut Scholarship Foundation
Friday, September 2, 2016
Eva Hansen, an undergraduate in the Benoit Lab, has been selected by the Astronaut Scholarship Foundation (ASF) to receive $10,000 in scholarships this academic year.
Eva is one of just 40 students selected nationwide this year for the honor. She is the fourth University of Rochester student to receive the ASF Scholarship and the first within the University of Rochester Department of Biomedical Engineering. She was chosen based on her unique aptitude for research and ingenuity in science and technology, as well as exemplary academic performance.
Eva's research involves drug delivery approaches to protect healthy tissue from the effects of radiation, as experienced in cancer therapy and in travel beyond low Earth orbit. She is mentored by MD/PhD student Jomy Varghese.
The ASF began in 1984 when the six surviving Mercury 7 astronauts came together to aid the United State in retaining its world leadership in science and technology by providing scholarship to the very best and brightest STEM students.
Benoit receives NIH funding for project: “A novel anti-caries approach to modulate virulence of cariogenic biofilms”
Thursday, September 1, 2016
Danielle Benoit and Hyun Koo of University of Pennsylvania recently received an NIH Research Project Grant (R01) for their project, “A novel anti-caries approach to modulate virulence of cariogenic biofilms"
Abstract: The development of novel chemotherapeutic approaches against cariogenic biofilms is challenging. Bacteria within biofilms are enmeshed in an exopolysaccharides (EPS)-rich matrix. Furthermore, EPS-embedded bacteria also create highly protected and acidic microenvironments that promote cariogenic biofilm build-up and acid-dissolution of tooth enamel. To overcome these remarkable challenges, our previous NIH supported (DE018023) studies developed a potent anti-caries approach by combining food-derived antibiofilm agents (myricetin and farnesol) with fluoride. We demonstrated that these agents in combination severely compromise EPS-matrix assembly and cariogenic biofilm development, resulting in a highly effective anti-caries therapy in vivo. Despite promising activity, there are limitations for further development and clinical translation of this approach. Both farnesol and myricetin are insoluble in aqueous solutions. In addition, retention of these agents at tooth-biofilm interface could be enhanced to maximize their efficacy in vivo. To address these hurdles, we have developed pH-responsive nanoparticle carriers (NPC) capable of co-encapsulating myricetin (Myr) and farnesol (Far) which were completely water-soluble, important towards practical formulations for human use. Furthermore, topically applied NPC bind avidly to pellicle and EPS, and accumulate within biofilms. Excitingly, NPC respond to acidic pH to release agents more rapidly at acidic (pathological) versus neutral (physiological) pH, greatly improving (~20-fold more effective than free agents) antibiofilm activity in vitro. We hypothesize that NPC will substantially amplify the efficacy of our combination therapy (CT) via increased solubility, retention and pH-activated release of active agents with fluoride. To support our hypothesis, Aim 1 will optimize physicochemical properties of NPC to improve targeted delivery of our agents, and thereby potentiate their antibiofilm efficacy. We will focus on increasing the kinetics of NPC pH-responsive drug release to ensure maximal release of the agents at pH consistent with the acidic biofilm milieu. Then, Aim 2 will evaluate the efficacy of optimized NPCs containing Myr and Far with fluoride (CT-NPC) using our in vitro cariogenic biofilm model. We have previously identified the major biological actions (EPS synthesis and acidogenicity) and molecular targets (gtfB, atpD) of our therapy. Thus, we will investigate how CT-NPC disrupts these virulence properties more effectively than CT using novel methods to assess spatiotemporal development of EPS matrix, acidic pH niches and gene expression in situ within intact 3D biofilms. Aim 3 will evaluate the efficacy of the developed CT-NPC in disrupting cariogenic biofilms and reducing dental caries in vivo using a rodent model of dental caries under clinically-relevant topical treatment regimen. CT-NPC will be also compared to ‘gold standards’ of caries prevention (fluoride) and antimicrobial therapy (chlorhexidine). Successful completion of these aims will lead to a highly efficacious and clinically-translatable therapy that may be superior to current anti-plaque/anti-caries modalities and will motivate formulation development for clinical studies.
Sue Zhang participates in Xerox Engineering Research Fellows Program
Monday, August 8, 2016
Sue Zhang, an undergraduate student working in the Benoit Lab, recently presented her work on "Degradable poly(ethylene glycol) hydrogels for temporal control of nanoparticle-mediated siRNA delivery" as a fellow in the Xerox Engineering Research Fellows Program. She was mentored by graduate student Yuchen Wang.
Summer students complete training in Benoit Lab
Tuesday, August 2, 2016
Jomy and Martha
The Benoit Lab was pleased to welcome two students for summer programs this year, Dina Collins and Martha Ormanoski. We’re grateful for exemplary mentoring from graduate students Dominic Malcolm (Dina Collins), Yuchen Wang (Sue Zhang), and Jomy Varghese (Martha Ormanoski) along the way.
Dina participated in SURF, a ten-week academic program designed to strengthen the science, clinical, and research skills of selected college students to enhance their competitiveness for careers in medicine and the biomedical sciences. SURF participants are selected from a national pool of candidates who have a demonstrated vision and commitment to improving the health status of diverse patient populations via patient care, research and/or teaching.
Dina and Martha
Cornell University student Martha Ormanoski participated in the Summer Scholars Program, which is designed for undergraduate students interested in the PhD degree in the Biological or Biomedical Sciences and for students with a potential interest in attending graduate school at the University of Rochester. Trainees participate in a centerpiece 10-week, hands-on, independent research project under the supervision of a faculty mentor, with guidance from graduate students and postdoctoral appointees.
Danielle presents seminar at University of New South Wales in Sydney, Australia
Tuesday, July 19, 2016
Danielle Benoit gave a seminar entitled, "Tissue Engineering and Drug Delivery Approaches for Bone Tissue Engineering" within the Department of Biomedical Engineering at the University of New South Wales, Sydney, Australia on July 1.
The Therapeutic Biomaterials Laboratory at the University of Rochester focuses on the development of polymer therapeutics for orthopaedic tissue engineering and drug delivery applications. There are myriad diseases of the skeleton that require regenerative approaches including bone grafts, osteoporosis, or delayed union or nonunion fractures. Specifically, in the case of allograft procedures, which are the ‘gold standard’ for massive bone defects, there exists a 60% failure rate within 10 years of implantation due to poor graft-host integration and microcrack propagation. Unlike allografts, autografts fully heal and integrate, mediated by the periosteum, a thin layer of osteogenic tissue surrounding bone.
Our efforts are two-fold to augment allograft healing: developing (1) cell transplantation approaches to recreate the periosteum and (2) targeted drug delivery systems to promote native periosteal cell recruitment and expansion to coordinate graft revitalization.
We have pioneered transplantation of mesenchymal stem cells (MSCs) within degradable hydrogels surrounding allografts as a tissue-engineered periosteum. In this approach, MSCs augment graft healing, as measured via increased graft vascularization (˜2.4-fold), endochondral bone formation (˜2.8-fold), and biomechanical strength (1.8-fold), as compared to untreated allografts. However, graft remodeling is slow compared to autografts, likely due to phenotypic differences of the PCs versus MSCs. Considering additional challenges associated with cell therapies, in parallel, we have developed a novel bone resorption site-targeted polymer therapeutic platform to promote PC recruitment and expansion.
We have shown that biodistribution of drug carriers after systemic administration can be dramatically altered to favor delivery to remodeling bone tissue through the incorporation of peptides that bind specifically to tartrate resistant acid phosphatase (TRAP), a protein deposited by osteoclast during the resorption phase of bone remodeling. Taken together, this work strives to advance our understanding of how the periosteum coordinates allograft healing and the design of regenerative strategies to recapitulate periosteal mediated healing.
Dr. Benoit delivers keynote at International Nanomedicine Conference
Friday, July 1, 2016
Danielle Benoit presented an invited Keynote at the International Nanomedicine Conference in Sydney, Australia on June 26-29. The talk 'Enzymatically-responsive poly(ethylene glycol) hydrogels for the controlled delivery of therapeutic peptides’ was hosted within the "Bioactive Materials" track.
Benoit Lab Sells Lemonade to Fight Childhood Cancer
Thursday, June 9, 2016
Danielle Benoit and fellow researchers will be serving lemonade and explaining their work on childhood cancer therapies this weekend on June 11th and 12th as part of a national effort organized by Alex’s Lemonade Stand Foundation.
“My lab is holding its 7th annual fundraiser to help Alex’s Lemonade Stand Foundation move one step closer to finding a cure for all children with cancer!” Benoit said. “You can join me by attending these events in the Rochester area or by making a donation to this page. The money you donate will pay for research to find better treatments and cures for childhood cancer. Please help kids and their families by providing desperately needed hope!”
Alex's Lemonade Stand Foundation (ALSF) emerged from the front yard lemonade stand of cancer patient Alexandra “Alex” Scott (1996-2004). In 2000, 4-year-old Alex announced that she wanted to hold a lemonade stand to raise money to help find a cure for all children with cancer. Since Alex held that first stand, the Foundation bearing her name has evolved into a national fundraising movement, complete with thousands of supporters across the country carrying on her legacy of hope.
For more information on the fundraiser, visit the website.
Dr. Wang receives AAFPRS Leslie Bernstein Resident Research Grant
Thursday, June 2, 2016
Congratulations to Weitao Wang who was selected to receive this year’s AAFPRS Leslie Bernstein Resident Research Grant for his proposal entitled Optimizing bone allograft in craniofacial defect reconstruction. Dr. Wang is a resident physician in the Otolaryngology Residency Program at the University of Rochester. He will be starting research in the Benoit lab this July based on this funding of $5,000.
Wang received the award from the Educational and Research Foundation for the American Academy of Facial Plastic & Reconstructive Surgery (AAFPRS), the American Academy of Otolaryngology – Head & Neck Surgery Foundation (AAO-HNSF) and the Centralized Otolaryngology Research Effort (CORE) Study Section.
Benoit Lab presents at World Biomaterials Congress
Saturday, May 21, 2016
Several members of the Benoit Lab presented their research at the 10th World Biomaterials Congress (WBC) this weekend, held in Montreal. The largest gathering of Biomaterial Research, the WBC includes over 1,200 oral presentations and 2,400 poster presentations. Their respective presentation topics are below.
Enzymatically-responsive poly(ethylene glycol) hydrogels for the controlled delivery of
Introduction: Therapeutic angiogenesis holds great potential within regenerative medicine approaches, where insufficient vascularization limits construct size, complexity, and anastomosis with host vasculature. Many pro-angiogenic approaches have been developed, often via delivery of angiogenic proteins or peptides. Peptides typically mimic the bioactivity of larger proteins or growth factors, and offer advantages over traditional protein delivery. However, like proteins, peptides suffer from rapid clearance and poor pharmacokinetics when delivered systemically. Therefore, a poly(ethylene glycol) (PEG) hydrogel-based platform technology was developed to control and sustain peptide drug release via matrix metalloproteinase (MMP) activity.
Localized and Sustained Delivery of small interference RNA (siRNA) from Poly(Ethylene Glycol) (PEG) Hydrogels to Enhance Fracture Healing
Introduction: Impaired fracture healing, which commonly stems from reduced mesenchymal stem cell (MSC) osteogenic capacity, is a major clinical challenge-. To augment MSC function and subsequent fracture healing, known inhibitors of bone formation can be downregulated. For example, mouse knockouts of WW domain containing E3 ubiquitin protein ligase 1 (WWP1) exhibit robust fracture healing. To realize clinically-relevant approaches to enhance fracture healing motivated by gene knockout studies, siRNA delivery can be exploited. However, siRNA delivery has many challenges including inefficient delivery vehicles that are incapable of local and sustained delivery of protected siRNA to achieve tissue regeneration. Thus, we developed and tested a hybrid nanoparticle (NP)/hydrogel delivery system where NPs protect siRNA and increase siRNA delivery efficiency, while PEG hydrogels provide localized and sustained siRNA delivery by controlling release of embedded siRNA/NPs.
Nanoparticle-mediated delivery of siRNAs modulates mesenchymal stem cell differentiation
Introduction: Mesenchymal stem cells (MSC) are an attractive cell source for tissue engineering approaches due to multilineage differentiation. However, controlling MSC fate is critical for tissue regeneration. microRNAs (miRNA) are known as ‘master regulators’ of differentiation, serving to integrate the myriad of complex signals driving differentiation . However, the use of small interfering RNA (siRNA), which are exogenous analogs of miRNA, to control MSC fate has been largely unexplored due to a paucity of delivery systems and poor appreciation for siRNAs necessary to achieve differentiation. Towards this end, we analyzed temporal expression of multiple miRNAs in MSCs undergoing osteogenesis in vitro. Subsequently, we used polymeric nanoparticles (NPs) previously shown to achieve successful siRNA delivery to MSCs  to deliver siRNA mimicking the identified miRNA while monitoring MSC differentiation.
Strategies to maintain acinar cell phenotype in vitro utilizing poly(ethylene glycol) hydrogels
Introduction: Over 500,000 people are diagnosed with head and neck cancers per year worldwide. Radiation therapy for these cancers causes extensive and permanent damage to secretory acinar cells within the salivary glands leading to permanent dry mouth for which no curative therapy exists. Cell-based therapies developed by the suspension culture of primary submandibular gland (SMG) cells has shown efficacy in restoring function after gland irradiation. However, regeneration is variable and the mechanism resulting in partial acinar regeneration in vivo is unclear,. To control acinar cell survival and function for subsequent transplantation in vivo, we are developing biomimetic poly(ethylene glycol) (PEG) hydrogels to culture primary SMG cells.
Peptide-functionalized polymers localize to remodeling osteoporotic bone
Introduction: Increased bone resorption by osteoclasts relative to bone formation by osteoblasts culminates in osteoporosis, a disease of low bone mass. There are myriad drugs in preclinical analyses that may enhance bone regeneration. However, these are largely small molecule drugs, which suffer from less than 1% bone accumulation. While bone targeting strategies exist, these approaches are general for bone matrix and not specific to where cellular remodeling is occurring, limiting targeted drug pharmacodynamics. We previously identified a peptide, TPLSYLKGLVTV, with high affinity to tartrate-resistant acid phosphatase (TRAP), a protein secreted by osteoclasts during the resorptive phase of bone remodeling. Targeting osteoanabolics to TRAP may enhance drug pharmacodynamics by increasing osteoblast activity specifically at sites of bone remodeling. This work developed TRAP-targeted polymer carriers as a platform for subsequent drug delivery approaches.
Taithera, Inc. partners with UR Ventures to Commercialize Bone-Targeted Therapeutic Agent
Monday, May 16, 2016
Taithera, Inc., a New York City based biotech company, and UR Ventures, the technology commercialization office of the University of Rochester, today announced plans to commercialize a bone-targeted therapeutic agent. This precision medicine technology, invented at the University of Rochester’s Center for Musculoskeletal Research, uses a peptide-based approach to deliver drugs directly to the bone for the diagnosis, treatment, and prevention of musculoskeletal diseases and disorders, including osteoporosis, bone cancer, bone fracture, bone allograft rejection, bone autograft rejection, and Paget’s disease.
J. Edward Puzas, Ph.D., the Donald and Mary Clark Professor of Orthopaedics, and Danielle Benoit, Ph.D., Associate Professor of Biomedical Engineering and Chemical Engineering, co-led the development of this technology.
Taithera’s co-founder and Chief Science Officer, Mo Chen, Ph.D. received his doctorate at the University of Rochester and conducted research at the Center for Musculoskeletal Research.
Rochester has been conducting extensive research on this bone-targeting therapeutic agent for more than six years, and animal models show that this bone-targeting technology has high affinity for tartrate-resistant acid phosphatase, an enzyme left by osteoclasts – the cells responsible for bone resorption. This means that drugs can be conjugates, or paired with, this targeting technology to deliver those drugs directly to the bone. This will significantly improve bone biodistribution.
Dr. Benoit said, “I have spent more than a decade developing polymeric delivery systems for biotherapeutics. For the past six years, my research has focused on developing novel targeting systems for bone-specific delivery of therapeutics. The results we have seen from this research show signs of something really quite revolutionary. I am thrilled that the University of Rochester and Taithera are working together to commercialize this technology. I look forward to working closely with Taithera.”
Dr. Chen agrees. “There are few times in a scientist’s career when you see a new technology that stands a strong chance to significantly improve millions of lives,” he said. “The quality of the research and data at the University of Rochester is second to none. It is an honor to once again work with the Center for Musculoskeletal Research at the University of Rochester.”
Collaborative project recommended for funding through CTSI Pilot Studies Program
Thursday, May 12, 2016
A collaborative project involving Research Assistant Professor Ben Frisch and Associate Professor of Biomedical Engineering Danielle Benoit has been selected for funding. The proposal entitled, “Targeted delivery of cytotoxic agents for the eradication of leukemia stem cells in the bone marrow” was submitted for a pilot project grant through the Pilot Studies Program of the CTSI earlier this year. The program considered the application to be highly meritorious and deserving of a priority score.
Andrew Shubin successfully defends Ph.D. thesis!
Tuesday, May 10, 2016
Congratulations to Andrew Shubin for a successfully defending his Ph.D. Thesis! Andrew worked in the Benoit Lab, and his project, Poly(ethylene glycol) hydrogels for salivary gland regeneration, was supported by the National Institute for Dental and Craniofacial Research (R01 DE022949) and a Ruth Kirschstein National Research Service Award Fellowship through the National Cancer Institute (F30 CA183320).
Jomy Varghese successfully defends proposal
Tuesday, May 10, 2016
Congratulations to Jomy Varghese for a successful defense of his proposal! Joey is currently a graduate student in the Benoit Lab, and his current project is "Engineered Nanoparticles to Radioprotect Salivary Tissue” (Supported by an NCI fellowship).
Graduate student Jomy Varghese awarded NCI Fellowship Grant
Sunday, May 1, 2016
Jomy Varghese, a graduate student working in the Benoit Lab, was recently awarded an F30 Fellowship Grant from the National Cancer Institute (NCI). His project is titled “Engineered Nanoparticles to Radioprotect Salivary Tissue” and deals with improving radiotherapy.
Project Description: Head and neck cancers comprise 6% of malignancies diagnoses annually, affecting 40,000 in the US and over 550,000 patients worldwide, who will then go on to receive radiotherapy. Radiation-induced xerostomia carries a significant risk for subsequent life threatening pathology and profoundly diminished quality of life by interfering with patients’ ability to eat and sleep. We propose novel nanoparticle platforms for radioprotection via localized, controlled delivery of siRNA and antioxidant strategies, which have the potential to prevent xerostomia altogether for our patients, and to improve radiotherapy significantly.
Proposal by Frisch, Fasan and Benoit receives University Research Award
Thursday, April 28, 2016
A collaborative project involving Research Assistant Professor Ben Frisch, Associate Professor of Chemistry Rudi Fasan, and Associate Professor of Biomedical Engineering Danielle Benoit has been chosen as one of the 2016-17 University Research Awards. One of just eight applications chosen by senior research leadership, the proposal entitled, “Targeted delivery of cytotoxic agents for the eradication of leukemia stem cells in the bone marrow” will be funded $72,600.
Benoit receives highly competitive score on NIH R01
Sunday, April 10, 2016
Danielle Benoit and Hyun Koo of University of Pennsylvania recently received an outstanding score of 8 percent on an NIH Research Project Grant (R01.) The description of their project, “A novel anti-caries approach to modulate virulence of cariogenic biofilms” is below:
The development of novel chemotherapeutic approaches against cariogenic biofilms is challenging. Bacteria within biofilms are enmeshed in an exopolysaccharides (EPS)-rich matrix. Furthermore, EPS-embedded bacteria also create highly protected and acidic microenvironments that promote cariogenic biofilm build-up and acid-dissolution of tooth enamel. To overcome these remarkable challenges, our previous NIH supported (DE018023) studies developed a potent anti-caries approach by combining food-derived antibiofilm agents (myricetin and farnesol) with fluoride. We demonstrated that these agents in combination severely compromise EPS-matrix assembly and cariogenic biofilm development, resulting in a highly effective anti-caries therapy in vivo. Despite promising activity, there are limitations for further development and clinical translation of this approach. Both farnesol and myricetin are insoluble in aqueous solutions. In addition, retention of these agents at tooth-biofilm interface could be enhanced to maximize their efficacy in vivo. To address these hurdles, we have developed pH-responsive nanoparticle carriers (NPC) capable of co-encapsulating myricetin (Myr) and farnesol (Far) which were completely water-soluble, important towards practical formulations for human use. Furthermore, topically applied NPC bind avidly to pellicle and EPS, and accumulate within biofilms. Excitingly, NPC respond to acidic pH to release agents more rapidly at acidic (pathological) versus neutral (physiological) pH, greatly improving (~20-fold more effective than free agents) antibiofilm activity in vitro. We hypothesize that NPC will substantially amplify the efficacy of our combination therapy (CT) via increased solubility, retention and pH-activated release of active agents with fluoride. To support our hypothesis, Aim 1 will optimize physicochemical properties of NPC to improve targeted delivery of our agents, and thereby potentiate their antibiofilm efficacy. We will focus on increasing the kinetics of NPC pH-responsive drug release to ensure maximal release of the agents at pH consistent with the acidic biofilm milieu. Then, Aim 2 will evaluate the efficacy of optimized NPCs containing Myr and Far with fluoride (CT-NPC) using our in vitro cariogenic biofilm model. We have previously identified the major biological actions (EPS synthesis and acidogenicity) and molecular targets (gtfB, atpD) of our therapy. Thus, we will investigate how CT-NPC disrupts these virulence properties more effectively than CT using novel methods to assess spatiotemporal development of EPS matrix, acidic pH niches and gene expression in situ within intact 3D biofilms. Aim 3 will evaluate the efficacy of the developed CT-NPC in disrupting cariogenic biofilms and reducing dental caries in vivo using a rodent model of dental caries under clinically-relevant topical treatment regimen. CT-NPC will be also compared to ‘gold standards’ of caries prevention (fluoride) and antimicrobial therapy (chlorhexidine). Successful completion of these aims will lead to a highly efficacious and clinically-translatable therapy that may be superior to current anti-plaque/anti-caries modalities and will motivate formulation development for clinical studies.
Benoit Aims to Develop a Drug Delivery System to Treat Osteoporosis Through NSF CAREER Award
Friday, April 8, 2016
Last year, BME Professor Danielle Benoit received a Faculty Early Career Development (CAREER) award, the most prestigious grants given by the National Science Foundation to junior faculty members. This article details her research and presents her tips for junior faculty members interested in applying for a CAREER award.
"The challenge with drug delivery to bone tissue is that there's currently no good way to target the drugs exactly where they are needed," says Danielle Benoit, the James P. Wilmot Distinguished Associate Professor of Biomedical Engineering. Her goal: Develop a drug delivery system that can be targeted to specific parts of the skeleton to treat osteoporosis.