Jan 29 2009
Scientists at NanoBio Corp. and the University of Michigan have demonstrated in the laboratory that their novel topical nanoemulsion kills the highly resistant strains of bacteria that cause chronic illness and death among individuals with cystic fibrosis.
The findings are significant because they represent a new model for treating resistant bacteria that lead to pulmonary failure in patients with cystic fibrosis, according to the study authors. Results of the in vitro study are published in the January issue of Antimicrobial Agents and Chemotherapy.
“Respiratory tract infections are the primary cause of death in persons with cystic fibrosis, and there are simply no effective therapies for patients infected with Burkholderia and other bacterial species that are resistant to all known antibiotics,” said John LiPuma, M.D., professor and associate chair for research in the department of pediatrics at the University of Michigan. “The nanoemulsion we tested was bactericidal against all but two of 150 bacterial strains, regardless of their levels of resistance, and it inhibited the growth of all the strains.”
Currently, oral or intravenous antibiotics serve as frontline therapy against cystic fibrosis–related bacterial infections. But systemic drugs often fail to reach the airways with sufficient strength to subdue the bacteria or to penetrate the thick sputum and bacterial biofilms that coat the bacteria. The rising prevalence of drug-resistant strains of bacteria has also reduced the efficacy of frontline antibiotics, both oral and intravenous, according to LiPuma, lead author of the study.
In the present study, the scientists applied various concentrations of NanoBio’s topical nanoemulsion to 150 multi–drug resistant and panresistant (completely resistant) bacteria obtained from the lungs of patients with cystic fibrosis. All strains of bacteria except two were killed by a concentration representing one-sixteenth the nanoemulsion formulation that has been used by NanoBio in recent clinical trials to treat skin infections.
“The strength of a topical or inhaled therapy is that you can achieve high local concentrations of the drug that you could never achieve with an oral systemic drug because it would cause systemic toxicity,” said James R. Baker, Jr., M.D., founder and chairman of NanoBio Corp. “We can nebulize our nanoemulsion so that it is deposited directly into the lungs to kill these highly resistant infections that cannot be effectively treated with available antibiotics.”
The nanoemulsion also demonstrated bactericidal activity in the presence of cystic fibrosis sputum and against bacterial biofilms, protective coatings that surround bacterial colonies and block the penetration of drugs.
“Based on preclinical and clinical safety data from NanoBio’s topical anti-infective products, we believe that we can safely deliver nanoemulsion concentrations to the lung that will be effective in killing the targeted bacteria,” said LiPuma. “The goal is to reduce bacterial populations to a level that the body can effectively manage so that the patient has fewer acute episodes and hospitalizations.”
NanoBio, a spin-out from the University of Michigan, is currently conducting preclinical nebulization and toxicity studies with multiple nanoemulsion formulations. The company expects to initiate a phase 1 study in humans with cystic fibrosis in 2010.