Antimicrobial Agents

Shanta Modak, PhD is a research scientist at Columbia University Medical Center who was inducted as a fellow to the National Academy of Inventors in 2014 for her work to develop infection-resistant medical devices. In collaboration with Professors of Surgery Henry M. Spotnitz, MD, and Mark A. Hardy, MD, Dr. Modak developed a new formulation in reducing infections associated with implantable cardioverter defibrillators (ICD) and a silver sulfadiazine cream effective for wound healing.

Examples of her inventions include antibacterial central venous catheters and soft tissue patches, which are now widely used in hospitals to reduce device-associated infection. Current studies in her laboratory include development of biofilm-resistant endotracheal tubes and urinary catheters as well as compositions for skin and surface disinfection. Please see more detailed descriptions below.

  1. Studies on the effectiveness of a novel coating composition to render medical devices Biofilm resistant 

    A technology to develop biofilm resistant medical devices has been developed. This technology is tailored to have a unique drug release pattern ideal for biofilm resistant antimicrobial medical device i.e. the device prevents adherence of bacteria and biofilm formation on its surface, but does not release therapeutic amount of antimicrobials to prevent systemic infection. Devices coated using this novel technology show an initial (within 3 days) of release of 10-20% of the antimicrobials which inactivate pathogens introduced from the insertion site, thus lowering potential for microbial colonization on the surface of device. Thereafter, the daily release is insignificant and the rest of the antimicrobials remain on the surface for a prolonged period of time, helping to prevent subsequent microbial adherence and biofilm formation.

    Biofilm resistant Urinary catheters (UC) and endotracheal tubes ( ETT) prepared using this technology exhibit a broader antimicrobial spectrum than the currently available antibacterial Silver coated UC and ETT especially against gram negative organisms and yeast and prevent bacterial biofilm formation for a prolonged period.

    Most importantly, this novel technology uses combination of hydrophilic-hydrophobic polymers as the matrix system to incorporate antimicrobials which renders the surface highly lubricious. This lubricious polymeric surface on the UC and ETT meet the need for an ideal device which makes insertion easier and thus providing more comfort to the patient avoiding the need for an overcoat with hydrogels. Current practice to improve lubricity of the urinary catheter surface is using a hydrogel overcoat. This extra step is time consuming and costly.

  2. Evaluation of the wound healing efficacy of a topical cream containing silver sulfadiazine and wound healing agents in various surface wounds

    In collaboration with Mark Hardy M.D, Professor of Surgery, a new silver sulfadiazine cream with wound healing properties was developed and has been found to be more effective than the currently used silvadene cream in animal models. Evaluation of the effectiveness of this cream in diabetic wounds, pressure ulcers, burn wounds, and surgical site infection will be conducted.

  3. Evaluation of the antimicrobial efficacy of a non-irritant skin cleanser for use in babies

    Currently 2% chlorhexidine solution is used in hospitals to bathe adult patients as well as newborns. Use of this solution causes skin irritation and dermatitis especially in babies. A non-irritating skin cleanser containing synergistic combination of low concentrations chlorhexidine and benzalkonium chloride and an anti-irritant hydrogel has been developed. The antibacterial efficacy of this cleanser has been found to be similar to 2% chlorhexidine solution in our preliminary in vitro pigskin test. A large scale study is planned in collaboration with a skin cleanser manufacturing company before using it in a hospital settings.

  4. Study of a Triclosan–free antimicrobial composition for use for skin and surface disinfection

    A broad spectrum antimicrobial composition containing botanicals has been developed. This composition has been found to enhance the efficacy of known disinfectant products with performance deficiency. Detailed studies to determine the broad spectrum efficacy of products containing this novel composition will be conducted.