Antibacterial protection of suture material by chlorhexidine-functionalized polyelectrolyte multilayer films

Antimicrobial-coated sutures versus non-coated sutures in reducing surgical site infection: An updated systematic review and meta-analysis

PURPOSE

Antimicrobial-coated sutures are one of the strategies to avoid surgical site infection (SSI) caused by microbial colonization on the surface of surgical sutures. This study aims to investigate the effectiveness of antimicrobial-coated sutures in reducing SSI and develop the latest systematic evaluation evidence for clinical SSI prevention and the use of antimicrobial-coated sutures.

METHODS

We searched the databases of Medline, Embase, CINAHL, Cochrane, African Index Medicus, and WHO Global Health from October 10th, 1990 to March 3rd, 2023 with language restricted to English, Spanish, and French. Meta-analysis was used to evaluate the impact of antimicrobial-coated sutures on SSI and whether their effectiveness is influenced by the type of sutures or wounds. Subgroup analyses were conducted based on type of sutures and wounds. Finally, quality of the retrieved evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

26 RCTs and 9 OBSs met the inclusion criteria. Antimicrobial sutures significantly reduced SSI risk (RCTs: OR: 0.74, 95% CI [0.63-0.87], p = 0.0002; OBSs: OR: 0.61, 95% CI [0.48-0.76], p ＜ 0.0001). Only subgroup analysis of Polydioxanone Suture (PDS) Plus vs. PDS, Vicryl Plus vs. Vicryl and mixed wounds revealed consistent results in favour of antimicrobial-coated sutures. According to GRADE, the quality of RCTs evidence is moderate, while that of OBSs evidence is low.

CONCLUSION

Antimicrobial-coated sutures are effective in reducing the risk of postoperative SSI among a large number of surgical patients. However, the available evidence is of moderate/low quality and many studies had conflicts of interest.

Enhancing Sustainability and Antifungal Properties of Biodegradable Composites: Caffeine-Treated Wood as a Filler for Polylactide

This study investigates the suitability of using caffeine-treated and untreated black cherry (Prunus serotina Ehrh.) wood as a polylactide filler. Composites containing 10%, 20%, and 30% filler were investigated in terms of increasing the nucleating ability of polylactide, as well as enhancing its resistance to microorganisms. Differential scanning calorimetry studies showed that the addition of caffeine-treated wood significantly altered the crystallization behavior of the polymer matrix, increasing its crystallization temperature and degree of crystallinity. Polarized light microscopic observations revealed that only the caffeine-treated wood induced the formation of transcrystalline structures in the polylactide. Incorporation of the modified filler into the matrix was also responsible for changes in the thermal stability and decreased hydrophilicity of the material. Most importantly, the use of black cherry wood treated with caffeine imparted antifungal properties to the polylactide-based composite, effectively reducing growth of Fusarium oxysporum, Fusarium culmorum, Alternaria alternata, and Trichoderma viride. For the first time, it was reported that treatment of wood with a caffeine compound of natural origin alters the supermolecular structure, nucleating abilities, and imparts antifungal properties of polylactide/wood composites, providing promising insights into the structure-properties relationship of such composites.

Engineering and polymeric composition of drug-eluting suture: A review

Sutures are the most popular surgical implants in the global surgical equipment market. They are used for holding tissues together to achieve wound closure. However, controlling the body's immune response to these "foreign bodies" at site of infection is challenging. Natural polymers such as collagen, silk, nylon, and cotton, and synthetic polymers such as polycaprolactone, poly(lactic-co-glycolic acid), poly(p-dioxanone) and so forth, contribute the robust foundation for the engineering of drug-eluting sutures. The incorporation of active pharmaceutical ingredients (APIs) with polymeric composition of suture materials is an efficient way to reduce inflammatory reaction in the wound site as well as to control bacterial growth, while allowing wound healing. The incorporation of polymeric composition in surgical sutures has been found to add high flexibility as well as excellent physical and mechanical properties. Fabrication processes and polymer materials allow control over drug-eluting profiles to effectively address wound healing requirements. This review outlines and discusses (a) polymer materials and APIs used in suture applications, including absorbable and nonabsorbable sutures; (b) suture structures, such as monofilament, multifilament, barded and smart sutures; and (c) the existing manufacturing techniques for drug-eluting suture production, including electrospinning, melt-extrusion and coating.

Local drug delivery from surgical thread for area-specific anesthesia

The application of surgical suture-thread and the systemic analgesics regimens for pain control in the postoperative surgery remain the criterion standard. However, these medications have daunting adverse effects on the body's innate pain management system. To address this issue, we have developed a local analgesic-loaded suture system which could be efficiently used for surgical repair with localized sedation effect. The drug-loaded conventional suture has modified by adhesive poly-dopamine coating with the local anesthetic lidocaine. The surface modifications have been ascertained by FE-SEM imaging. The tensile strength of suture ensures required elasticity to use in surgical skin closure. In vitro drug release and the in vivo local analgesia was achieved one day after surgery and persisted approximately for one week in 80% of treated animals. Our pre-clinical results suggest that drug-loaded surgical thread may be an effective strategy for improving the overall outcome.

Bacterial colonisation of suture material after routine neurosurgical procedures: relevance for wound infection

BACKGROUND

Wound healing impairment is a serious problem in surgical disciplines which may be associated with chronic morbidity, increased cost and patient discomfort. Here we aimed to investigate the relevance of bacterial colonisation on suture material using polymerase chain reaction (PCR) to detect and taxonomically classify bacterial DNA in patients with and without wound healing problems after routine neurosurgical procedures.

METHODS

Repeat surgery was performed in 25 patients with wound healing impairment and in 38 patients with well-healed wounds. To determine the presence of bacteria, a 16S rDNA-based PCR detection method was applied. Fragments of 500 bp were amplified using universal primers which target hypervariable regions within the bacterial 16S rRNA gene. Amplicons were separated from each other by single-strand conformation polymorphism (SSCP) analysis, and finally classified using Sanger sequencing.

RESULTS

PCR/SSCP detected DNA of various bacteria species on suture material in 10/38 patients with well-healed wounds and in 12/25 patients with wound healing impairment including Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes and Escherichia coli. Microbiological cultures showed bacterial growth in almost all patients with wound healing impairment and positive results in PCR/SSCP (10/12), while this was the case in only one patient with a well-healed wound (1/10).

CONCLUSIONS

Colonisation of suture material with bacteria occurs in a relevant portion of patients with and without wound healing impairment after routine neurosurgical procedures. Suture material may provide a nidus for bacteria and subsequent biofilm formation. Most likely, however, such colonisation of sutures is not a general primer for subsequent wound infection.

Polyelectrolyte Multilayers: A Versatile Tool for Preparing Antimicrobial Coatings

The prevention of pathogen colonization of medical implants represents a major medical and financial issue. The development of antimicrobial coatings aimed at protecting against such infections has thus become a major field of scientific and technological research. Three main strategies are developed to design such coatings: (i) the prevention of microorganisms adhesion and the killing of microorganisms (ii) by contact and (iii) by the release of active compounds in the vicinity of the implant. Polyelectrolyte multilayer (PEM) technology alone covers the entire widespread spectrum of functionalization possibilities. PEMs are obtained through the alternating deposition of polyanions and polycations on a substrate, and the great advantages of PEMs are that (i) they can be applied to almost any type of substrate whatever its shape and composition; (ii) various chemical, physicochemical, and mechanical properties of the coatings can be obtained; and (iii) active compounds can be embedded and released in a controlled manner. In this article we will give an overview of the field of PEMs applied to the design of antimicrobial coatings, illustrating the large versatility of the PEM technology.

A prospective clinical evaluation of the effects of chlorhexidine, warm saline mouth washes and microbial growth on intraoral sutures

INTRODUCTION

Post operative care of sutured wound is important after surgery. Sutured wounds within the oral cavity are kept clean through frequent rinses with either normal saline, chlorhexidine mouth rinses, hydrogen peroxide diluted with saline, or fresh tap water.

PATIENTS AND METHODS

The patients were randomised into 3 groups (A, B and C). The container used had 34 chlorhexidine, 34 warm saline and 32 warm water mouth rinses. The latter served as control. All selected patients had scaling and polishing done preoperatively when needed. All participants in each group did not receive antibiotics but received analgesics (paracetamol 1 g 8 h for 5 days,).

RESULTS

There were 49 females and 51 males, in the age range between 18 and 50 years. Microorganisms were found to grow on sutures with streptococcus viridians predominating followed by staphylococcus epidermides. The effects of chlorhexidine, warm saline and warm tap water mouth washes were not statistically significant.

CONCLUSION

Chlorhexidine, warm salt water and warm tap water averagely produced the same number of colony forming units of bacteria, which shows that the three different mouth washes are equally effective as post-operative mouth rinses after oral surgery.

Novel Coating of Surgical Suture Confers Antimicrobial Activity Against Porphyromonas gingivalis and Enterococcus faecalis

BACKGROUND

The oral cavity is colonized by >10(9) bacteria, many of which can increase heart disease risk when seeded into the bloodstream. Most dentoalveolar surgeries require the use of surgical sutures. Suture placement and removal can increase the risk of postoperative infection and bacteremia. The aim of this study is to evaluate the antimicrobial activity of a novel quaternary ammonium compound, K21, when coated on different suture materials.

METHODS

The periodontal pathogen Porphyromonas gingivalis and the endodontic species Enterococcus faecalis were grown to early log phase and inoculated on enriched Brucella blood agar, on which were placed identical lengths of surgical suture (chromic gut, polyester suture, silk, and nylon suture) and control unwaxed dental floss impregnated with K21 at 5%, 10%, 20%, and 25% volume/volume in ethanol vehicle. Controls included the following: 1) sutures treated with vehicle; 2) untreated sutures; and 3) unwaxed floss. Zones of inhibition in millimeters were measured at five randomized sites per suture/floss for each concentration and material used. Mean ± SD of zones of inhibition were calculated, and analysis of variance (P <0.05) was used to determine whether differences were statistically significant.

RESULTS

The results indicate that K21-coated suture at concentrations ranging from 5% to 25%, depending on the type of suture, have antimicrobial activity for P. gingivalis and E. faecalis. Nylon suture coated with K21 at 5%, 10%, 20%, and 25% resulted in zones ranging from 3 to 11 mm. Polyester suture was more effective at lower K21 concentrations with 5% (P = 0.0031), 10% (P = 0.0011), and 20% (P = 0.0002), yielding 7.5, 8.3, and 10.5 mm zones of inhibition. K21-coated silk suture yielded significant zones of inhibition at 25% (P <0.0001), whereas chromic gut was effective at K21 concentrations of 5% (P = 0.0081) and 25% (P <0.0001).

CONCLUSION

It is concluded that K21-coated surgical sutures have antimicrobial activity for bacterial species of direct relevance to postoperative infection and bacteremia.

Development of silver nano-coatings on silk sutures as a novel approach against surgical infections

The infections give rise to a range of clinical problems and prolong hospitalization with increased healthcare costs. Moreover, persistent infections exasperate the problem of antibiotic resistance. The aim of this study was the development of effective and low-cost antibacterial silver coatings on surgical sutures by adopting an innovative photochemical deposition process to prevent early contamination of surgical wounds. The silver deposition technology adopted in this work is an innovative process based on the in situ photoreduction of a silver solution. The samples were dipped in the silver solution and then exposed to UV radiation in order to induce the synthesis of silver clusters on the surface of the suture. The homogeneous distribution of silver particles on the surface and on the cross-section of the treated sutures was demonstrated. All the antibacterial studies clearly demonstrated that the use of novel silver treated sutures could represent clinical advantages in terms of the prevention of surgical infections against bacterial colonization. The silver coating deposited on the sutures demonstrated no cytotoxic effect on a selected cell population. The results obtained suggested that the antibacterial silver-coated sutures developed in this work could represent an interesting alternative to conventional sutures, with evident advantages in terms of prevention of the surgical infections and on the health costs. In addiction, very low concentrations of silver significantly inhibited the microbial load, without affecting the cell viability.

Sutures coated with antiseptic pomade to prevent bacterial colonization: a randomized clinical trial

OBJECTIVE

The aim of this study was to assess if an antiseptic pomade could reduce the bacterial colonization on multifilament sutures.

STUDY DESIGN

A randomized clinical trial was conducted with 40 volunteer patients of both sexes aged 18-70, randomly separated into experimental (n = 20) and control (n = 20) groups. The experimental group received pomade-coated sutures (iodoform + calendula) and the control group uncoated sutures. Two millimeters of the suture was harvested from each patient from the 1st to the 15th postoperative day. The bacteria that had adhered to them were cultured. The number of colony-forming units per milliliter (CFU/mL) was determined and the groups were compared using the Mann-Whitney statistical test (P < .05).

RESULTS

The experimental group showed a significant reduction in bacterial growth compared with the control group (P = .002).

CONCLUSIONS

In this experimental model, the antiseptic pomade was effective in reducing bacterial colonization on silk braided sutures.

Polymeric multilayers that localize the release of chlorhexidine from biologic wound dressings

Biologic wound dressings contain animal-derived components and are susceptible to high infection rates. To address this issue, we report an approach that permits incorporation of non-toxic levels of the small molecule antiseptic 'chlorhexidine' into biologic dressings. The approach relies on the fabrication of polyelectrolyte multilayer (PEMs) films containing poly(allylaminehydrochloride) (PAH), poly(acrylicacid) (PAA), and chlorhexidine acetate (CX) on elastomeric poly(dimethylsiloxane) (PDMS) sheets. The PEMs (20-100 nm thick) are subsequently stamped onto the wound-contact surface of a synthetic biologic dressing, Biobrane, which contains collagen peptides. Chlorhexidine loading in the PEMs was tailored by tuning the number of (CX/PAA) bilayers deposited, providing burst release of up to 0.98 ± 0.06 μg/cm(2) of CX over 24 h, followed by zero-order release of 0.35 ± 0.04 μg/cm(2)/day for another week. Although the CX concentrations released were below the reported in vitro cytotoxicity limit (5 μg/mL over 24 h) for human dermal fibroblasts, they killed 4 log(10) counts of pathogenic bacteria Staphylococcus aureus in solution. The CX/PEMs could be stamped onto Biobrane with high efficiency to provide CX release kinetics and in vitro antibacterial activity similar to that on PDMS stamps. In a full-thickness 'splinted' dermal wound-model in normal wild-type mice, the CX-functionalized Biobrane showed no decrease in either its adherence to the wound-bed or wound closure rate over 14 days. The murine wounds topically inoculated with ∼10(5) CFU/cm(2) of S. aureus and treated with CX-functionalized Biobrane demonstrated a 3 log(10) decrease in the wound's bacterial burden within 3 days, compared to persistent bacterial colonization found in wounds treated with unmodified Biobrane (n = 10 mice, p < 0.005). Overall, this study presents a promising approach to prevent bacterial colonization in wounds under biologic dressings.

Electrospun drug-eluting sutures for local anesthesia

We have developed a local anesthetic-eluting suture system which would combine the function and ubiquity of the suture for surgical repair with the controlled release properties of a biodegradable polymeric matrix. Drug-free and drug-loaded poly(lactic-co-glycolic acid) (PLGA) sutures were fabricated by electrospinning, with or without the local anesthetic bupivacaine. The tensile strength of the electrospun sutures decreased as drug content increased, but strains remained relatively similar across all groups. Sutures released their entire drug payload over the course of 12 days and maintained approximately 12% of their initial tensile strength after 14 days of incubation in vitro. In a rat skin wound model, local analgesia was achieved 1 day after surgery and lasted approximately 1 week in 90% of treated animals (n=10, p<0.05), and all wounds were able to heal normally without the need for further reinforcement. The sutures caused tissue reaction in vivo that was comparable to that seen with a commercially available suture composed of PLGA. Such sutures may enhance perioperative analgesia and mitigate the need for standard postoperative opioid analgesics.

An in vitro bacterial adhesion assessment of surface-modified medical-grade PVC

Medical-grade polyvinyl chloride was surface modified by a multistep physicochemical approach to improve bacterial adhesion prevention properties. This was fulfilled via surface activation by diffuse coplanar surface barrier discharge plasma followed by radical graft copolymerization of acrylic acid through surface-initiated pathway to render a structured high density brush. Three known antibacterial agents, bronopol, benzalkonium chloride, and chlorhexidine, were then individually coated onto functionalized surface to induce biological properties. Various modern surface probe techniques were employed to explore the effects of the modification steps. In vitro bacterial adhesion and biofilm formation assay was performed. Escherichia coli strain was found to be more susceptible to modifications rather than Staphylococcus aureus as up to 85% reduction in adherence degree of the former was observed upon treating with above antibacterial agents, while only chlorhexidine could retard the adhesion of the latter by 50%. Also, plasma treated and graft copolymerized samples were remarkably effective to diminish the adherence of E. coli.