RESUMO
To date, few publications describe CEC's properties and possible applications-thus, further evaluation of these properties is a point of interest. The present in vitro model study aimed to evaluate a carboxyethylchitosan (CEC) gel with a degree of substitution of 1, cross-linked with glutaraldehyde at a polymer:aldehyde molar ratio of 10:1, as a potential carrier for delivering bacteriophages to various pH-fixed media (acidic, alkaline), and including gastrointestinal tract (GIT) variable medium. A quantitative analysis of bacteriophages released from the gel was performed using photon correlation spectrophotometry, and phage activity after emission into medium was evaluated using the spot test. The results showed that the CEC gel's maximum swelling ratios were at a nearly neutral alkaline pH. Increasing temperature enhances the swelling ratio of the gel independent from pH, up to 1127% at 37 °C and alkaline pH. The UV and photon correlation spectrophotometry showed equal gel release kinetics in both fixed media with acidic (pH = 2.2) and alkaline (pH = 7.4) pH environments at 37 °C, with the maximum release within two hours. However, phage lytic activity in the spot test during this simulation was absent. At the same time, we obtained an opaque phage lytic activity in the alkaline pH-fixed medium for at least three hours. Phages released from the tested CEC gel in different pHs suggest that this gel could be used for applications that require fast release at the treatment site both in acidic and alkaline pH. Such treatment sites could be a wound or even soil with mild acidic or alkaline pH. However, such CEC gel is not suitable as a delivery system to the GIT because of possible transported acid-sensitive agent (such as phages) release and destruction already in the stomach.
RESUMO
Implant-associated infections are the most costly problem in modern orthopedics due to the continued increase in the occurrence of antibiotic-resistant bacterial strains that requires the development of new effective antimicrobials. A non-randomized, prospective, open-label, with historical control study on the use of combined phage/antibiotic therapy of periprosthetic joint infection (PJI) was carried out. Forty-five adult patients with deep PJI of the hip joint were involved in the study, with a 12-month follow-up after one-stage revision surgery. Patients from a prospective study group (SG, n = 23) were treated with specific phage preparation and etiotropic antibiotics, whereas patients from a retrospective comparator group (CG, n = 22) received antibiotics only. The rate of PJI relapses in the SG was eight times less than that in the CG: one case (4.5%) versus eight cases (36.4%), p = 0.021. The response rate to treatment was 95.5% (95% confidence interval (CI) = 0.7511-0.9976) in the SG and only 63.6% (95% CI = 0.4083-0.8198) in the CG. The odds ratio for PJI relapse in patients of the SG was 0.083 (95% CI = 0.009-0.742), which was almost 12 times lower than that in the CG. The obtained results support the efficacy of the combined phage-antibiotic treatment of PJI.
