Characteristics and clinical assessment of antibiotic delivery by chitosan sponge in the high-risk diabetic foot: a case series

Formulation and Comprehensive Evaluation of Biohybrid Hydrogel Membranes Containing Doxycycline or Silver Nanoparticles

Complicated wounds often require specialized medical treatments, and hydrogels have emerged as a popular choice for wound dressings in such cases due to their unique properties and the ability to incorporate and release therapeutic agents. Our focus was to develop and characterize a new optimized formula for biohybrid hydrogel membranes, which combine natural and synthetic polymers, bioactive natural compounds, like collagen and hyaluronic acid, and pharmacologically active substances (doxycycline or npAg). Dynamic (oscillatory) rheometry confirmed the strong gel-like properties of the obtained hydrogel membranes. Samples containing low-dose DOXY showed a swelling index of 285.68 ± 6.99%, a degradation rate of 71.6 ± 0.91% at 20 h, and achieved a cumulative drug release of approximately 90% at pH 7.4 and 80% at pH 8.3 within 12 h. The addition of npAg influenced the physical properties of the hydrogel membranes. Furthermore, the samples containing DOXY demonstrated exceptional antimicrobial efficacy against seven selected bacterial strains commonly associated with wound infections and complications. Biocompatibility assessments revealed that the samples exhibited over 80% cell viability. However, the addition of smaller-sized nanoparticles led to decreased cellular viability. The obtained biohybrid hydrogel membranes show favorable properties that render them suitable for application as wound dressings.

Chitosan Sponges Are Associated With Higher Rates of Wound Complications Compared to Calcium Sulfate Beads

Background In this study, we aimed to determine if there is a difference in the rates of wound dehiscence, delayed union, nonunion, and unanticipated surgery after the use of bioabsorbable local antibiotic-delivery systems (LADS), specifically comparing antibiotic-impregnated calcium sulfate pellets (Osteoset-T, Wright Medical Technology Inc., Arlington, TN, USA, hereafter referred to as beads) and chitosan sponge (Sentrex BioSponge, Bionova Medical, Germantown, TN, USA, hereafter referred to as sponges) in the management of acute and chronic extremity wounds. Methodology We conducted a retrospective comparative cohort study in the setting of a level 1 trauma center. All patients who received either beads or sponges as an adjunct to surgical debridement from January 2010 to December 2017 were included, and 136 patients met the inclusion criteria. The intervention studied was extremity wounds that were treated with bioabsorbable LADS, either beads or sponges. The main outcome measurement was wound dehiscence and the need for unanticipated surgery. Results Of the 136 patients in the study cohort, 78% (106/136) were treated with beads, and 22% (30/136) were treated with sponges. Of the 136 patients, 50 (37%) experienced wound dehiscence, and 49 patients required unanticipated surgery. Overall, 62% (31/50) of patients with wound dehiscence and 67.4% (33/49) of patients requiring unanticipated surgery were seen in the bead cohort (p = 0.0001 and 0.025, respectively). However, in multivariable analyses, we found that the odds of having wound dehiscence and undergoing unanticipated surgery were, respectively, 4.9 (p = 0.001) and 2.8 (p = 0.021) times more likely to occur in the sponge than in the bead group. Conclusions Sentrex sponges appear to be associated with higher rates of wound dehiscence and the need for unanticipated surgery compared to Osteoset beads.

Development and Evaluation of an Injectable Chitosan/β-Glycerophosphate Paste as a Local Antibiotic Delivery System for Trauma Care

Complex open musculoskeletal wounds are a leading cause of morbidity worldwide, partially due to a high risk of bacterial contamination. Local delivery systems may be used as adjunctive therapies to prevent infection, but they may be nondegradable, possess inadequate wound coverage, or migrate from the wound site. To address this issue, a thermo-responsive, injectable chitosan paste was fabricated by incorporating beta-glycerophosphate. The efficacy of thermo-paste as an adjunctive infection prevention tool was evaluated in terms of cytocompatibility, degradation, antibacterial, injectability, and inflammation properties. In vitro studies demonstrated thermo-paste may be loaded with amikacin and vancomycin and release inhibitory levels for at least 3 days. Further, approximately 60% of thermo-paste was enzymatically degraded within 7 days in vitro. The viability of cells exposed to thermo-paste exceeded ISO 10993-5 standards with approximately 73% relative viability of a control chitosan sponge. The ejection force of thermo-paste, approximately 20 N, was lower than previously studied paste formulations and within relevant clinical ejection force ranges. An in vivo murine biocompatibility study demonstrated that thermo-paste induced minimal inflammation after implantation for 7 days, similar to previously developed chitosan pastes. Results from these preliminary preclinical studies indicate that thermo-paste shows promise for further development as an antibiotic delivery system for infection prevention.

A randomized, controlled study to investigate the efficacy and safety of a topical gentamicin-collagen sponge in combination with systemic antibiotic therapy in diabetic patients with a moderate or severe foot ulcer infection

BACKGROUND

An adjunctive topical therapy with gentamicin-sponges to systemic antibiotic therapy might improve the healing of infected diabetic foot ulcers (DFUI).

METHODS

Single-center, investigator-blinded pilot study, randomizing (1:1) the gentamicin-sponge with systemic antibiotic versus systemic antibiotics alone for patients with DFUI.

RESULTS

We included 88 DFUI episodes with 43 patients in the gentamicin-sponge arm and 45 in the control arm. Overall, 64 (64/88; 73%) witnessed total clinical cure, 13 (15%) significant improvement, and 46 (52%) showed total eradication of all pathogens at the final visit. Regarding final clinical cure, there was no difference in favour of the gentamicin-sponges (26/45 vs. 31/43; p = 0.16). However, the gentamicin-sponge arm tended to a more rapid healing. In multivariate analysis adjusting for the case-mix, the variable "gentamicin-sponge" was not significantly associated with "cure and improvement". Gentamicin-sponges were very well tolerated, without any attributed adverse events.

CONCLUSIONS

The gentamicin-sponge was very well tolerated, but did not significantly influence overall cure.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT01951768 ). Date 2 April 2013.