# Sustained release gel enabling one-stage treatment of prosthetic joint infection

> **NIH NIH R44** · SONORAN BIOSCIENCES, INC. · 2020 · $999,516

## Abstract

Prosthetic joint infections (PJIs) are a serious complication of total joint replacement
surgery. PJIs accounted for about $6 billion in healthcare costs in 2018. Unfortunately, treatment
of PJI is under-reimbursed, and healthcare reforms are putting increasing economic pressure on
hospitals to bear the high costs of treating these infections. New technologies are badly needed
to improve the quality of care and costs associated with treating PJI.
 PJIs are caused by bacteria in biofilms which require extreme sustained concentrations of
antimicrobials to eradicate. PJIs are treated with two surgeries. In the first, the infected implant
and tissues are removed (debridement) followed by local delivery of high concentrations of
antimicrobials to eradicate any residual biofilm contamination. Currently, local delivery is achieved
using bone cement "spacers" which require removal in a second surgery. A product that provides
local delivery and is also compatible with insertion of a permanent implant would enable effective
PJI treatment in a single surgery, improving patient outcomes and reducing costs.
 We have developed a new degradable sustained-release carrier, SB Gel, which is capable
of delivering high and sustained antimicrobial concentrations throughout a surgical site, including
over the entire surface of a joint prosthesis. SB Gel is the only material to provide high, sustained
antibiotic release sufficient to eliminate contamination in the surgical site (including biofilm),
compatibility on all implant and tissue surfaces (including articulating surfaces), and safe
dissolution over time to allow for normal healing without requiring later removal. SB Gel is loaded
with the antimicrobials tobramycin and vancomycin in a formulation designated as SBG002.
These drugs are effective against bacteria responsible for over 95% of PJIs. Preliminary studies
demonstrate that SBG002 provides biofilm-eradicating antimicrobial levels in tissue, is compatible
with bone-implant ingrowth and normal tissue healing, is safe at multiples of a human equivalent
dose, and has unmatched effectiveness in successfully treating (20/20) an animal model of
implant-associated biofilm infection in a single surgery treatment.
 We now propose continuing development in a Phase IIB project to complete all remaining
work to bring SBG002 to readiness for a Phase 1 clinical trial including submission of an
Investigational New Drug (IND) application to the FDA. In Aim 1, we will complete all remaining
IND-enabling GLP toxicology and genotoxicity studies. In Aim 2, we will conduct all required
manufacturing-related activities, including production and characterization of clinical trial material.
Aim 2 will conclude with preparation and filing of an IND application for SBG002.

## Key facts

- **NIH application ID:** 9971460
- **Project number:** 5R44AI142978-04
- **Recipient organization:** SONORAN BIOSCIENCES, INC.
- **Principal Investigator:** Derek James Overstreet
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $999,516
- **Award type:** 5
- **Project period:** 2019-08-01 → 2022-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9971460

## Citation

> US National Institutes of Health, RePORTER application 9971460, Sustained release gel enabling one-stage treatment of prosthetic joint infection (5R44AI142978-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9971460. Licensed CC0.

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