A review of sutures and other skin closure materials

Dual-Modified Hyaluronic Acid for Tunable Double Cross-Linked Hydrogel Adhesives

Conventional techniques for the closure of wounds, such as sutures and staples, have significant drawbacks that can negatively impact wound healing. Tissue adhesives have emerged as promising alternatives, but poor adhesion, low mechanical properties, and toxicity have hindered their widespread clinical adoption. In this work, a dual modified, aldehyde and methacrylate hyaluronic acid (HA) biopolymer (HA-MA-CHO) has been synthesized through a simplified route for use as a double cross-linked network (DCN) hydrogel (HA-MA-CHO-DCN) adhesive for the effective closure and sealing of wounds. HA-MA-CHO-DCN cross-links in two stages: initial cross-linking of the aldehyde functionality (CHO) of HA-MA-CHO using a disulfide-containing cross-linker, 3,3'-dithiobis (propionic hydrazide) (DTPH), leading to the formation of a self-healing injectable gel, followed by further cross-linking via ultraviolet (UV) initiated polymerization of the methacrylate (MA) functionality. This hydrogel adhesive shows a stable swelling behavior and remarkable versatility as the storage modulus (G') has shown to be highly tunable (103-105 Pa) for application to many different wound environments. The new HA-MA-CHO-DCN hydrogel showed excellent adhesive properties by surpassing the burst pressure and lap-shear strength for the widely used bovine serum albumin-glutaraldehyde (BSAG) glue while maintaining excellent cell viability.

Biodegradable suture development-based albumin composites for tissue engineering applications

Recent advancements in the field of biomedical engineering have underscored the pivotal role of biodegradable materials in addressing the challenges associated with tissue regeneration therapies. The spectrum of biodegradable materials presently encompasses ceramics, polymers, metals, and composites, each offering distinct advantages for the replacement or repair of compromised human tissues. Despite their utility, these biomaterials are not devoid of limitations, with issues such as suboptimal tissue integration, potential cytotoxicity, and mechanical mismatch (stress shielding) emerging as significant concerns. To mitigate these drawbacks, our research collective has embarked on the development of protein-based composite materials, showcasing enhanced biodegradability and biocompatibility. This study is dedicated to the elaboration and characterization of an innovative suture fabricated from human serum albumin through an extrusion methodology. Employing a suite of analytical techniques-namely tensile testing, scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA)-we endeavored to elucidate the physicochemical attributes of the engineered suture. Additionally, the investigation extends to assessing the influence of integrating biodegradable organic modifiers on the suture's mechanical performance. Preliminary tensile testing has delineated the mechanical profile of the Filament Suture (FS), delineating tensile strengths spanning 1.3 to 9.616 MPa and elongation at break percentages ranging from 11.5 to 146.64%. These findings illuminate the mechanical versatility of the suture, hinting at its applicability across a broad spectrum of medical interventions. Subsequent analyses via SEM and TGA are anticipated to further delineate the suture's morphological features and thermal resilience, thereby enriching our comprehension of its overall performance characteristics. Moreover, the investigation delves into the ramifications of incorporating biodegradable organic constituents on the suture's mechanical integrity. Collectively, the study not only sheds light on the mechanical and thermal dynamics of a novel suture material derived from human serum albumin but also explores the prospective enhancements afforded by the amalgamation of biodegradable organic compounds, thereby broadening the horizon for future biomedical applications.

No difference in prevalence of postoperative iliopsoas tendinitis in patients undergoing arthroscopic hip surgery when using absorbable versus non-absorbable suture for capsular closure

PURPOSE

The volume of arthroscopic hip surgery has increased dramatically in recent years with iliopsoas tendinitis (IPT) being one of the most common complications of this procedure. The purpose of this study is to investigate the prevalence of post-operative IPT in patients who undergo arthroscopic hip surgery with capsular closure using absorbable versus non-absorbable suture.

METHODS

This is a single center, single surgeon, retrospective analysis performed between August 2007 and May 2023 comparing two cohorts who underwent hip arthroscopy. Patients were divided into those who underwent surgery with capsular closure using absorbable (Vicryl®, Johnson and Johnson, New Brunswick, NJ) suture and those who underwent capsular closure with non-absorbable suture (Suturetape, Arthrex, Naples FL). All patients who underwent primary or revision hip arthroscopy and were at least 2 months post-operation were initially included in the study.

RESULTS

Between August 2007 and May 2023 a total of 1513 hip arthroscopy surgeries were performed. Within this cohort, 1421 hips underwent hip arthroscopy with non-absorbable suture and 64 hips underwent surgery with absorbable suture. There was no significant difference between the proportion of IPT in the non-absorbable cohort (2.3%) versus the absorbable cohort (1.6%) (P = 0.669).

CONCLUSION

Capsular closure with Absorbable sutures was non-inferior to capsular closure with non-absorbable sutures with respect to the proportion of post-operative IPT following hip arthroscopy for FAI. Additionally, the proportion of post-operative IPT was found to be significantly higher in patients undergoing revision versus primary hip arthroscopy, regardless of capsular closure suture type.

LEVEL OF EVIDENCE

IV.

Doping of casted silk fibroin membranes with extracellular vesicles for regenerative therapy: a proof of concept

Bioactive material concepts for targeted therapy have been an important research focus in regenerative medicine for years. The aim of this study was to investigate a proof-of-concept composite structure in the form of a membrane made of natural silk fibroin (SF) and extracellular vesicles (EVs) from gingival fibroblasts. EVs have multiple abilities to act on their target cell and can thus play crucial roles in both physiology and regeneration. This study used pH neutral, degradable SF-based membranes, which have excellent cell- and tissue-specific properties, as the carrier material. The characterization of the vesicles showed a size range between 120 and 180 nm and a high expression of the usual EV markers (e.g. CD9, CD63 and CD81), measured by nanoparticle tracking analysis (NTA) and single-EV flow analysis (IFCM). An initial integration of the EVs into the membrane was analyzed using scanning and transmission electron microscopy (SEM and TEM) and vesicles were successfully detected, even if they were not homogeneously distributed in the membrane. Using direct and indirect tests, the cytocompatibility of the membranes with and without EVs could be proven and showed significant differences compared to the toxic control (p < 0.05). Additionally, proliferation of L929 cells was increased on membranes functionalized with EVs (p > 0.05).

Oral soft tissue biopsy surgery: Current principles and key tissue stabilization techniques

There are different kinds of benign and malignant lesions in the oral cavity. Clinically, definite diagnosis can be confirmed only by doing adequate surgical biopsy and subsequent histopathological examination. Inadequate biopsy technique, unsuitable selection of the location for biopsy, inappropriate tissue handling and record of patients' information may lead to artifacts and misdiagnosis by the oral pathologists. Soft tissue stabilization is a challenge during oral surgery procedures. It needs the cooperation of operator, assistants, and patients to overcome the difficulty and ensure the successful outcome. In this article, we reviewed the procedures for clinical surgical biopsy, and raised three current tissue stabilization methods including fingers and gauze stabilization, stabilization with chalazion forceps and adapted instruments, and stabilization with retraction sutures. Moreover, some limitations were also presented. Clinician should examine the clinical characteristics of the oral lesion, the surrounding anatomical structures, and their own clinical experience and preference to select the appropriate tool. More understanding of these biopsy and tissue stabilization methods can effectively improve the biopsy procedures and obtain adequate tissues for histopathological examination and subsequent issue of an accurate pathological report.

Bioactive citrate-based polyurethane tissue adhesive for fast sealing and promoted wound healing

As a superior alternative to sutures, tissue adhesives have been developed significantly in recent years. However, existing tissue adhesives struggle to form fast and stable adhesion between tissue interfaces, bond weakly in wet environments and lack bioactivity. In this study, a degradable and bioactive citrate-based polyurethane adhesive is constructed to achieve rapid and strong tissue adhesion. The hydrophobic layer was created with polycaprolactone to overcome the bonding failure between tissue and adhesion layer in wet environments, which can effectively improve the wet bonding strength. This citrate-based polyurethane adhesive provides rapid, non-invasive, liquid-tight and seamless closure of skin incisions, overcoming the limitations of sutures and commercial tissue adhesives. In addition, it exhibits biocompatibility, biodegradability and hemostatic properties. The degradation product citrate could promote the process of angiogenesis and accelerate wound healing. This study provides a novel approach to the development of a fast-adhering wet tissue adhesive and provides a valuable contribution to the development of polyurethane-based tissue adhesives.

A hydrogel-based first-aid tissue adhesive with effective hemostasis and anti-bacteria for trauma emergency management

BACKGROUND

Clinical tissue adhesives remain some critical drawbacks for managing emergency injuries, such as inadequate adhesive strength and insufficient anti-infection ability. Herein, a novel, self-healing, and antibacterial carboxymethyl chitosan/polyaldehyde dextran (CMCS/PD) hydrogel is designed as the first-aid tissue adhesive for effective trauma emergency management.

METHODS

We examined the gel-forming time, porosity, self-healing, antibacterial properties, cytotoxicity, adhesive strength, and hemocompatibility. Liver hemorrhage, tail severance, and skin wound infection models of rats are constructed in vivo, respectively.

RESULTS

Results demonstrate that the CMCS/PD hydrogel has the rapid gel-forming (~ 5 s), good self-healing, and effective antibacterial abilities, and could adhere to tissue firmly (adhesive strength of ~ 10 kPa and burst pressure of 327.5 mmHg) with excellent hemocompatibility and cytocompatibility. This suggests the great prospect of CMCS/PD hydrogel in acting as a first-aid tissue adhesive for trauma emergency management. The CMCS/PD hydrogel is observed to not only achieve rapid hemostasis for curing liver hemorrhage and tail severance in comparison to commercial hemostatic gel (Surgiflo ®) but also exhibit superior anti-infection for treating acute skin trauma compared with clinical disinfectant gel (Prontosan ®).

CONCLUSIONS

Overall, the CMCS/PD hydrogel offers a promising candidate for first-aid tissue adhesives to manage the trauma emergency. Because of the rapid gel-forming time, it could also be applied as a liquid first-aid bandage for mini-invasive surgical treatment.

Dermatoscopic and Dermatopathologic Features of a 3-Year-Old Buried Polypropylene Suture

ABSTRACT

Cutaneous foreign bodies are a well-known cause of delayed wound healing and complications such as abscesses, fistula formation, and secondary infections. Polypropylene sutures are widely utilized in cutaneous surgery because they easily travel through tissues while eliciting minimal tissue reactions. Despite these advantages, retained polypropylene sutures can cause complications. The authors report a case of a retained polypropylene suture that remained buried after a total excision 3 years prior. It started to cause cutaneous symptoms when the patient began exercising 1 week prior to presentation. The authors also examine the dermatoscopic and dermatopathologic features and other complications related to retained polypropylene sutures that have been reported in the literature.

Preparation of Surgical Thread from a Bioplastic Based on Nopal Mucilage

Currently, natural materials represent a sustainable option for the manufacture of biopolymers with numerous industrial applications and characteristics comparable with synthetic materials. Nopal mucilage (NM) is an excellent natural resource for the synthesis of bioplastics (BPs). In the present research, the fabrication of biopolymers by using NM is addressed. Changes in the plasticizer (sorbitol and cellulose) concentration, in addition to the implementation of two sources of starch (corn starch (CS) and potato starch (PS)) to obtain the surgical thread, were analyzed. The NM extracted was close to 14% with ethanol. During the characterization of the extract, properties such as moisture, humidity, viscosity, and functional groups, among others, were determined. In the CS and PS analysis, different structures of the polymeric chains were observed. BP degradation with different solvents was performed. Additionally, the addition of sorbitol and cellulose for the BP mixtures presenting the highest resistance to solvent degradation and less solubility to water was conducted. The obtained thread had a uniform diameter, good elasticity, and low capillarity compared to other prototypes reported in the literature.

A highly elastic absorbable monofilament suture fabricated from poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

To address the growing demand for more elastic sutures free from unwanted knot loosening, we fabricated an absorbable monofilament suture from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and subjected it to physical property characterization and performance evaluation (in vitro and in vivo degradability tests and a porcine abdominal wall suture test). As this flexible, highly stretchable, and difficult-to-untie suture exhibited additional advantages of small knot size and medium to long-term bioabsorbability, it was concluded to be a safe alternative to existing monofilament sutures, with far-reaching potential applications.

Comparison of Therapeutic Effects Between Electroacupuncture and Thread-Embedded Acupuncture in Obese Patients Undergoing a Dietary Intervention

Objective

Obesity is an epidemic with an increasing prevalence in developing countries. The condition affects almost all physiologic functions of the body and is a significant threat to public health. Treatment of obesity is often difficult and expensive. Pharmacologic therapy has many side-effects. Acupuncture, a nonpharmacologic therapy, has shown promising results for treating obesity. Electroacupuncture (EA) and thread-embedded acupuncture (TEA) can be used. The aim of this study was to analyze the therapeutic effects of EA and TEA, using polydioxanone (PDO), on weight loss, waist circumference, and plasma-leptin concentrations in obese patients undergoing a dietary intervention.

Materials and Methods

This single-blinded, randomized clinical trial randomized 34 subjects into 2 groups: EA and TEA. In the EA group, EA was administered 3 times per week for 4 weeks (a total of 12 sessions). In the TEA group, EA was administered only once. Body weight and waist circumference were measured at baseline, and on days 3, 7, 14, 21, and 28 (end) of the trial. Plasma-leptin concentrations were measured at the beginning and end of the trial.

Results

There was a significant decrease in body weight and waist circumference in the groups before and after treatment (P < 0.001), and a significant decrease in plasma-leptin concentrations in the EA (P = 0.012) and TEA groups (P = 0.001). There were no significant differences between the groups in weight loss (P = 0.621), waist circumference (P = 0.545), and plasma-leptin concentration (P = 0.784).

Conclusions

EA and PDO TEA are equally effective for reducing body weight, waist circumference, and plasma-leptin concentrations in obese patients undergoing dietary interventions. However, TEA is more time-efficient than EA.

Tensile strength of a novel superficial suture pattern compared to traditional suture patterns in a cadaveric human skin model

BACKGROUND

The suture material and pattern utilized to maintain the skin edges in proximity allows for successful primary wound healing. No prior studies have evaluated the tensile strength of different suture patterns on human cadaveric skin. This study evaluates the tensile strength of four single suture patterns: simple (S), horizontal-mattress (HM), vertical-mattress (VM), and a novel stich termed Lindeque locking (LL).

METHODS

Four skin closure patterns were tested on human cadaveric skin using 3-0 nylon - S, HM, VM, LL - totaling four groups with twelve samples each. A tensioning device applied 1 N of force/second in a linear fashion. The primary outcome measures were: (i) wound dehiscence force, and (ii) ultimate load to failure. Statistics included one-way ANOVA with post-hoc Tukey tests.

RESULTS

The LL stitch had the greatest dehiscence force (198.60 N) and ultimate load to failure force (211.13 N) but was only significantly greater on both outcomes versus HM (104.81 N; 95% confidence interval [CI], 65.7 to 121.9; p< 0.001) and (120.79 N; 95% CI, 63.5 to 117.2; p < 0.001), respectively. There was no significant difference between LL and S for dehiscence, nor for the ultimate load to failure (186.90 N and 195.08 N, respectively). The LL pattern was significantly greater for an ultimate load to failure, but not for dehiscence when compared to VM (173.9 N and 171.1 N, respectively). Of all patterns, HM had significantly less withstanding force.

CONCLUSIONS

The Lindeque Locking stitch demonstrated the greatest dehiscence force and tensile strength. It may decrease the risk of wound dehiscence for high tension wounds.

Brow gliding: A new non-surgical concept for almond upturned eyes

BACKGROUND

The eyes are one of the most prominent features of the face. To date, a vast majority of procedures have been described for periorbital rejuvenation. Among them, non-surgical threading is an alternative and minimally invasive technique.

OBJECTIVE

We developed a new non-surgical threading technique to achieve long-lasting almond-shaped upturned eyes with brow lifting that we call "brow gliding". We developed a new non-surgical threading technique to achieve long-lasting almond-shaped upturned eyes with brow lifting that we call "brow gliding". Here, we present details of our procedure and the clinical experience of our patients who have at least a 6-month follow-up period.

METHODS AND MATERIALS

We used polydioxanone cog threads in combination with knots to lift the lateral sides of the brows and eyes. By burying these knots in the subcutaneous tissue and extending the threads to the scalp fascia, we were able to spread the load of the threads over multiple stable structures in order to achieve an effective lifting impact.

RESULTS

According to the subjective assessment scale, all patients described the improvements as very good or beyond expectations after the procedure. During the follow-up period, 4 of 34 (11.8%) patients stated it was very good and 19 of 34 (55.9%) patients stated that it was still beyond expectations.

CONCLUSION

The Brow Gliding technique is a promising office-based cosmetic procedure for periorbital aesthetics with a prominent outcome and minimally invasive fashion.

Tissue adhesive, adhesive tape, and sutures for skin closure of paediatric surgical wounds: prospective randomized clinical trial

BACKGROUND

Tissue adhesive, adhesive tape, and sutures are used to close surgical incisions. However, it is unclear which produces the best results in children, and whether combination wound closure is better than sutures alone.

METHODS

In this parallel randomised controlled trial (ANZCTR: ACTRN12617000158369), children (aged 18 years or less) undergoing elective general surgical or urological procedures were randomized to skin closure with sutures alone, sutures and adhesive tape, or sutures and tissue adhesive. Participants were assessed 2 weeks, 6 weeks, and more than 6 months after operation. Outcomes included wound cosmesis (clinician- and parent-rated) assessed using four validated scales, parental satisfaction, and wound complication rates.

RESULTS

295 patients (333 wounds) were recruited and 277 patients (314 wounds) were included in the analysis. Tissue adhesive wounds had poorer cosmesis at 6 weeks: median 10-point VAS score 7.7 with sutures alone, 7.5 with adhesive tape, and 7.0 with tissue adhesive (P = 0.014). Respective median scores on a 100-point VAS were 80.0, 77.2, and 73.8 (P = 0.010). This difference was not sustained at over 6 months. There was no difference in parent-rated wound cosmesis at 6 weeks (P = 0.690) and more than 6 months (P = 0.167): median score 9.0 with sutures alone, 10.0 with adhesive tape, and 10.0 with tissue adhesive at both stages. Parental satisfaction was similar at all points, with a median score of 5 (very satisfied) for all groups. There was one instance of wound dehiscence in the tissue adhesive group and no wound infections.

CONCLUSION

Short-term wound cosmesis was poorer with tissue adhesive although it is unclear whether this difference is sustained in the long-term. There were no differences between techniques for the study outcomes.

REGISTRATION NUMBER

ACTRN12617000158369 (ANZCTR) (https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372177&isReview=true).

Fluorescent Hybrid Material Based on Natural Spider Silk and Carbon Dots for Bioapplication

Since the outcome of an operation largely depends on the quality of wound healing, it is one of the most challenging stages in surgery. Today, wound closure is mostly undertaken by means of a surgical suture. Good surgical sutures are biocompatible and biodegradable and possess excellent mechanical properties. Preferably, these sutures demonstrate optical activity for bacteria detection as there is a risk of surgical site infections. In this study, a solution, which fulfills all the requirements for manufacturing a multifunctional hybrid material, is proposed. In this work, a method for the in situ modification of spider silk with fluorescent carbon dots has been developed. The basic concept is the use of silk fibers as both the main framework for tissue regeneration and a carbon source during carbon dot synthesis. The resulting hybrid material exhibits strong photoluminescence in the red region of the spectrum (590 nm) when irradiated with blue light (480 nm). The proposed approach potentially allows for simultaneous wound closure and pathogen detection.

Suture Materials, Needles, and Methods of Skin Closure: What Every Hand Surgeon Should Know

Sutures are used ubiquitously in surgery and are the most implanted materials in hand surgery. However, surgical training does not routinely include formal education on stitching materials or needles. Rather, suture familiarity is passed down by common use throughout training. We focus on a brief history and evolution of suture materials and suture needles, their material and mechanical properties, hand surgery-specific applications, other methods of skin closure (staples, skin glue, and adhesive strips), a cost analysis, and advances in musculoskeletal suturing, with a look toward the future. Equipped with a fundamental knowledge of suture needles and suture materials, hand surgeons will be better prepared to select the most appropriate, situation-specific tools.

Zinc-nutrient element based alloys for absorbable wound closure devices fabrication: Current status, challenges, and future prospects

The need for the development of load-bearing, absorbable wound closure devices is driving the research for novel materials that possess both good biodegradability and superior mechanical characteristics. Biodegradable metals (BMs), namely: magnesium (Mg), zinc (Zn) and iron (Fe), which are currently being investigated for absorbable vascular stent and orthopaedic implant applications, are slowly gaining research interest for the fabrication of wound closure devices. The current review presents an overview of the traditional and novel BM-based intracutaneous and transcutaneous wound closure devices, and identifies Zn as a promising substitute for the traditional materials used in the fabrication of absorbable load-bearing sutures, internal staples, and subcuticular staples. In order to further strengthen Zn to be used in highly stressed situations, nutrient elements (NEs), including calcium (Ca), Mg, Fe, and copper (Cu), are identified as promising alloying elements for the strengthening of Zn-based wound closure device material that simultaneously provide potential therapeutic benefit to the wound healing process during implant biodegradation process. The influence of NEs on the fundamental characteristics of biodegradable Zn are reviewed and critically assessed with regard to the mechanical properties and biodegradability requirements of different wound closure devices. The opportunities and challenges in the development of Zn-based wound closure device materials are presented to inspire future research on this rapidly growing field.

A multifunctional electronic suture for continuous strain monitoring and on-demand drug release

Surgical sutures are widely used for closing wounds in skin. However, the monitoring of wound integrity and promoting tissue regeneration at the same time still remains a challenge. To address this, we developed a drug-releasing electronic suture system (DRESS) to monitor the suture integrity in real-time and enhance tissue regeneration by triggered drug release. DRESS was fabricated by using a single fiber with a core-shell structure consisting of a stretchable conductive fiber core and a thermoresponsive polymer shell containing drugs. The highly conductive fiber core acts as a strain sensor that enables continuous monitoring of suture strain with high sensitivity (a gauge factor of ∼686) and mechanical durability (being able to endure more than 3000 stretching cycles). The thermoresponsive shell layer composed of flexible poly(vinyl alcohol) (PVA) grafted onto poly(N-isopropylacrylamide) (PNIPAm) facilitates on-demand drug release via Joule heating. The results of an in vitro scratch assay showed a 66% decrease in wound area upon heat-activation after 48 hours demonstrating the stimuli-responsive therapeutic efficacy of DRESS by promoting cell migration. Moreover, ex vivo testing on porcine skin demonstrated the applicability of DRESS as a electronic suture. The approach used for DRESS provides insight into multifunctional sutures and offers additional therapeutic and diagnostic options for clinical applications.

Short-Term Preclinical Application of Functional Human Induced Pluripotent Stem Cell-Derived Airway Epithelial Patches

Airway pathologies including cancer, trauma, and stenosis lack effective treatments, meanwhile airway transplantation and available tissue engineering approaches fail due to epithelial dysfunction. Autologous progenitors do not meet the clinical need for regeneration due to their insufficient expansion and differentiation, for which human induced pluripotent stem cells (hiPSCs) are promising alternatives. Airway epithelial patches are engineered by differentiating hiPSC-derived airway progenitors into physiological proportions of ciliated (73.9 ± 5.5%) and goblet (2.1 ± 1.4%) cells on a silk fibroin-collagen vitrigel membrane (SF-CVM) composite biomaterial for transplantation in porcine tracheal defects ex vivo and in vivo. Evaluation of ex vivo tracheal repair using hiPSC-derived SF-CVM patches demonstrate native-like tracheal epithelial metabolism and maintenance of mucociliary epithelium to day 3. In vivo studies demonstrate SF-CVM integration and maintenance of airway patency, showing 80.8 ± 3.6% graft coverage with an hiPSC-derived pseudostratified epithelium and 70.7 ± 2.3% coverage with viable cells, 3 days postoperatively. The utility of bioengineered, hiPSC-derived epithelial patches for airway repair is demonstrated in a short-term preclinical survival model, providing a significant leap for airway reconstruction approaches.

Engineered Bioactive Polymeric Surfaces by Radiation Induced Graft Copolymerization: Strategies and Applications

The interest in developing antimicrobial surfaces is currently surging with the rise in global infectious disease events. Radiation-induced graft copolymerization (RIGC) is a powerful technique enabling permanent tunable and desired surface modifications imparting antimicrobial properties to polymer substrates to prevent disease transmission and provide safer biomaterials and healthcare products. This review aims to provide a broader perspective of the progress taking place in strategies for designing various antimicrobial polymeric surfaces using RIGC methods and their applications in medical devices, healthcare, textile, tissue engineering and food packing. Particularly, the use of UV, plasma, electron beam (EB) and γ-rays for biocides covalent immobilization to various polymers surfaces including nonwoven fabrics, films, nanofibers, nanocomposites, catheters, sutures, wound dressing patches and contact lenses is reviewed. The different strategies to enhance the grafted antimicrobial properties are discussed with an emphasis on the emerging approach of in-situ formation of metal nanoparticles (NPs) in radiation grafted substrates. The current applications of the polymers with antimicrobial surfaces are discussed together with their future research directions. It is expected that this review would attract attention of researchers and scientists to realize the merits of RIGC in developing timely, necessary antimicrobial materials to mitigate the fast-growing microbial activities and promote hygienic lifestyles.

Comparison of Surgical Site Infection After Skin Closure by Prolene or Staples in Bilateral Simultaneous Knee Arthroplasty Patients: A Parallel Design Randomized Controlled Trial Protocol

Introduction:

Knee arthroplasty also known as the total knee replacement is an orthopedic surgical procedure done to resurface the knee that has been severely damaged by arthritis. After the completion of the surgical procedure, the skin closure is done. The optimal goal of skin closure after the procedure is to promote rapid healing and an acceptable cosmetic result while minimizing the risk of infection. Skin closure after knee arthroplasty is done by using either of the two widely used sutures i.e., polypropylene (Prolene) sutures or the skin staple sutures. There are no standard guidelines as which type of the suture should be used. The present study aims to compare the incidence of surgical site infections (superficial and deep) for Prolene vs staple sutures in the bilateral knee arthroplasty patients within 6 weeks for superficial and within 90 days for deep infection.

Methods:

This study will be conducted as an open blinded, parallel design, equivalence randomized controlled trial. The patients would be selected and randomized in 1:1 ratio to receive either of the two interventions i.e., Prolene or Staples. Patients undergoing unilateral or staged total knee replacement (TKR) were excluded.

Analysis:

The normality assessment will be done using Shapiro Wilk test. Cox proportional hazard regression will be used to check the univariate and multi-variable associations of independent variables with the outcome. Both intention to treat analysis and per protocol analysis would be performed.

Ethics and Dissemination:

All the required approvals will be taken from the ethical review committee. Informed consent will be taken form the patient to enroll him/her in the study. Results of the study will be disseminated to the study participants, public health and clinical professionals and would also be published in a reputable international journal.

The trial is registered at clinicaltrials.gov and UIN of the registry is NCT04492852.

Highlights

Time to closure of orthopaedic surgical incisions: a novel skin closure device versus conventional sutures

OBJECTIVE

New technologies are being developed to optimise healing of surgical incisions. BandGrip (US) is a micro-anchor skin closure device that replaces the need for subcuticular suturing and further dressing. The purpose of this study is to perform a matched cohort analysis comparing time to closure of surgical incisions between sutures and the novel skin closure device.

METHOD

Patients undergoing orthopaedic surgery in 2019 underwent skin closure with either conventional sutures or the novel skin closure device. Patients were divided into three groups according to their procedural incisions: anterior cruciate ligament reconstruction (ACLR); simple arthroscopy; and general incisions. Patients who underwent closure of their surgical incision with the novel skin closure device were matched with patients undergoing superficial closure with sutures. Statistical analysis was performed to compare time to closure per centimetre of skin incision between the groups.

RESULTS

A total of 86 patients were included in the study. Overall mean time to closure using the novel skin closure device was less than with sutures (8.6 seconds/cm versus 42.8 seconds/cm, respectively, p<0.001). Mean time to closure for ACLR incisions was 3.7 seconds/cm using the novel skin closure device and 35.5 seconds/cm using sutures (p<0.001). Mean time to closure for simple arthroscopy portals was 19 seconds/cm using the novel skin closure device and 47.6 seconds/cm using sutures (p<0.001).

CONCLUSION

BandGrip is a novel skin closure device that allows for efficient surgical incision closure. Time to surgical skin incision closure is significantly less with the use of the novel skin closure device when compared with conventional sutures.

Advances in carbohydrate-based polymers for the design of suture materials: A review

Suture materials constitute one of the largest biomedical material groups with a huge global market of $ 1.3 billion annually and employment in over 12 million procedures per year. Suture materials have radically evolved over the years, from basic strips of linen to more advanced synthetic polymer sutures. Yet, the journey to the ideal suture material is far from over and we now stand on the brink of a new era of improved suture materials with greater safety and efficacy. This next step in the evolutionary timeline of suture materials, involves the use of natural, carbohydrate polymers that have, until recent years, never before been considered for suture material applications. This review exposes the latest and most important advancements in suture material development while digging deep into how natural, carbohydrate polymers can serve to advance this field.

Antimicrobial laser-activated sealants for combating surgical site infections

Surgical-site infections (SSIs) occur in 2-5% of patients undergoing surgery in the US alone, impacting 300 000-500 000 lives each year, and presenting up to 11 times greater risk of death compared to patients without SSIs. The most common cause of SSI is Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA) is the most common pathogen in community hospitals. Current clinical devices used for approximating incisions and traumatic lacerations include sutures, adhesives, tapes, or staples with or without antimicrobial incorporation. However, current closure technologies may not provide adequate protection against infection, are susceptible to wound dehiscence, and can result in delayed biomechanical recoveries. Laser-activated tissue repair is a sutureless technique in which chromophore-loaded sealants convert laser light energy to heat in order to induce rapid tissue sealing. Here, we describe the generation and evaluation of laser-activated sealant (LASE) biomaterials, in which, indocyanine green (ICG), an FDA-approved dye, was embedded in a silk fibroin matrix and cast into films as wound sealants. Silk-ICG films were subjected to different near-infrared (NIR) laser powers to identify temperatures optimal for laser sealing of soft tissues. A mathematical model was developed in order to determine the photothermal conversion efficiency of LASEs following laser irradiation. NIR laser activation of silk-ICG LASEs increased the recovery of skin biomechanical strength compared to sutured skin in full-thickness incisional wounds in immunocompetent mice, and live animal imaging indicated persistence of silk-ICG LASEs over several days. LASEs loaded with the antibiotic vancomycin demonstrated higher efficacies for combating MRSA infections in a mouse model of surgical site infection compared to antibacterial sutures. Our results demonstrate that LASEs can be loaded with antimicrobial drugs and may serve as new multifunctional biomaterials for rapid tissue sealing, repair and surgical site protection following surgery.

The influence of Ca and Cu additions on the microstructure, mechanical and degradation properties of Zn-Ca-Cu alloys for absorbable wound closure device applications

Novel ternary Zn-Ca-Cu alloys were studied for the development of absorbable wound closure device material due to Ca and Cu's therapeutic values to wound healing. The influence of Ca and Cu on the microstructure, mechanical and degradation properties of Zn were investigated in the as-cast state to establish the fundamental understanding on the Zn-Ca-Cu alloy system. The microstructure of Zn-0.5Ca-0.5Cu, Zn-1.0Ca-0.5Cu, and Zn0.5Ca-1.0Cu is composed of intermetallic phase CaZn13 distributed within the Zn-Cu solid solution. The presence of CaZn13 phase and Cu as solute within the Zn matrix, on the one hand, exhibited a synergistic effect on the grain refinement of Zn, reducing the grain size of pure Zn by 96%; on the other hand, improved the mechanical properties of the ternary alloys through solid solution strengthening, second phase strengthening, and grain refinement. The degradation properties of Zn-Ca-Cu alloys are primarily influenced by the micro-galvanic corrosion between Zn-Cu matrix and CaZn13 phase, where the 0.5% and 1.0% Ca addition increased the corrosion rate of Zn from 11.5 μm/y to 19.8 μm/y and 29.6 μm/y during 4 weeks immersion test.

Tissue adhesive and adhesive tape for pediatric wound closure: A systematic review and meta-analysis

BACKGROUND

Tissue adhesive (TiA), adhesive tape (AdT), and sutures can be used to close surgical wounds and lacerations in children. However, it is unclear which technique produces the best results.

METHODS

In this prospectively registered study, the PubMed, Ovid MEDLINE, Cochrane Library, Centre for Reviews and Dissemination Database, and ScienceDirect databases were searched. English language studies published between January 1980 and August 2017 evaluating TiA and/or AdT for primary skin closure of surgical wounds or lacerations in patients aged ≤18 years were included. Study endpoints included clinician-rated wound cosmesis and incidence of wound complications.

RESULTS

Thirty-one studies were included in the systematic review and 16 studies in the meta-analysis. Amongst heterogeneous studies, AdT yielded marginally better cosmetic outcomes than TiA (p = 0.04). There was no difference in cosmesis between sutured wounds and those closed with TiA (p = 0.2). No difference in overall risk of wound infection or dehiscence was identified when comparing TiA with AdT (p = 0.3), and TiA with sutures (p = 0.9 and 0.3 respectively).

CONCLUSIONS

TiA, AdT, and sutures can all be used for wound closure with equivalent risk of wound infection and dehiscence. AdT appears to convey better cosmesis. Further adequately powered studies directly comparing techniques are required.

LEVELS OF EVIDENCE

Level IV.

2D phosphorene nanosheets, quantum dots, nanoribbons: synthesis and biomedical applications

Phosphorene, also known as black phosphorus (BP), is a two-dimensional (2D) material that has gained significant attention in several areas of current research. Its unique properties such as outstanding surface activity, an adjustable bandgap width, favorable on/off current ratios, infrared-light responsiveness, good biocompatibility, and fast biodegradation differentiate this material from other two-dimensional materials. The application of BP in the biomedical field has been rapidly emerging over the past few years. This article aimed to provide a comprehensive review of the recent progress on the unique properties and extensive medical applications for BP in bone, nerve, skin, kidney, cancer, and biosensing related treatment. The details of applications of BP in these fields were summarized and discussed.

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.

An Accelerated Wound-Healing Surgical Suture Engineered with an Extracellular Matrix

A suture is a ubiquitous medical device to hold wounded tissues together and support the healing process after surgery. Surgical sutures, having incomplete biocompatibility, often cause unwanted infections or serious secondary trauma to soft or fragile tissue. In this research, UV/ozone (UVO) irradiation or polystyrene sulfonate acid (PSS) dip-coating is used to achieve a fibronectin (FN)-coated absorbable suture system, in which the negatively charged moieties produced on the suture cause fibronectin to change from a soluble plasma form into a fibrous form, mimicking the actions of cellular fibronectin upon binding. The fibrous fibronectin coated on the suture can be exploited as an engineered interface to improve cellular migration and adhesion in the region around the wounded tissue while preventing the binding of infectious bacteria, thereby facilitating wound healing. Furthermore, the FN-coated suture is found to be associated with a lower friction between the suture and the wounded tissue, thus minimizing the occurrence of secondary wounds during surgery. It is believed that this surface modification can be universally applied to most kinds of sutures currently in use, implying that it may be a novel way to develop a highly effective and safer suture system for clinical applications.

Polymeric Tissue Adhesives

Polymeric tissue adhesives provide versatile materials for wound management and are widely used in a variety of medical settings ranging from minor to life-threatening tissue injuries. Compared to the traditional methods of wound closure (i.e., suturing and stapling), they are relatively easy to use, enable rapid application, and introduce minimal tissue damage. Furthermore, they can act as hemostats to control bleeding and provide a tissue-healing environment at the wound site. Despite their numerous current applications, tissue adhesives still face several limitations and unresolved challenges (e.g., weak adhesion strength and poor mechanical properties) that limit their use, leaving ample room for future improvements. Successful development of next-generation adhesives will likely require a holistic understanding of the chemical and physical properties of the tissue-adhesive interface, fundamental mechanisms of tissue adhesion, and requirements for specific clinical applications. In this review, we discuss a set of rational guidelines for design of adhesives, recent progress in the field along with examples of commercially available adhesives and those under development, tissue-specific considerations, and finally potential functions for future adhesives. Advances in tissue adhesives will open new avenues for wound care and potentially provide potent therapeutics for various medical applications.

The effect of surgical suture material on osteoclast generation and implant-loosening

Background: Implant loosening - either infectious or aseptic- is a still a major complication in the field of orthopaedic surgery. In both cases, a pro-inflammatory peri-prosthetic environment is generated by the immune system - either triggered by bacteria or by implant wear particles - which leads to osteoclast differentiation and osteolysis. Since infectious cases in particular often require multiple revision surgeries, we wondered whether commonly used surgical suture material may also activate the immune system and thus contribute to loss of bone substance by generation of osteoclasts. Methods: Tissue samples from patients suffering from infectious implant loosening were collected intraoperatively and presence of osteoclasts was evaluated by histopathology and immunohistochemistry. Further on, human monocytes were isolated from peripheral blood and stimulated with surgical suture material. Cell supernatant samples were collected and ELISA analysis for the pro-inflammatory cytokine IL-8 was performed. These experiments were additionally carried out on ivory slices to demonstrate functionality of osteoclasts. Whole blood samples were incubated with surgical suture material and up-regulation of activation-associated cell surface markers CD11b and CD66b on neutrophils was evaluated by flow cytofluorometry analysis. Results: We were able to demonstrate that multinucleated giant cells form in direct vicinity to surgical suture material. These cells stained positive for cathepsin K, which is a typical protease found in osteoclasts. By in vitro analysis, we were able to show that monocytes differentiated into osteoclasts when stimulated with surgical suture material. Resorption pits on ivory slices provided proof that the osteoclasts were functional. Release of IL-8 into cell supernatant was increased after stimulation with suture material and was further enhanced if minor amounts of bacterial lipoteichoic acid (LTA) were added. Neutrophils were also activated by surgical suture material and up-regulation of CD11b and CD66b could be seen. Conclusion: We were able to demonstrate that surgical suture material induces a pro-inflammatory response of immune cells which leads to osteoclast differentiation, in particular in combination with bacterial infection. In conclusion, surgical suture material -aside from bacteria and implant wear particles- is a contributing factor in implant loosening.

A Prospective Randomized Control Study Comparing the Effects of Dermal Staples and Intradermal Sutures on Postoperative Scarring After Thyroidectomy

BACKGROUND

We compared cosmetic outcomes, pain intensity, and costs between dermal stapling and intradermal suturing in patients who underwent thyroidectomy through cervical incision.

PATIENTS AND METHODS

In total, 40 patients were randomly assigned to undergo thyroidectomy through a low cervical incision and dermal closure using either absorbable staples (n = 20, staple group) or interrupted intradermal sutures (n = 20, suture group). Wound complications, cosmetic outcomes (modified Stony Brook Scar Evaluation Scale [SBSES] and Manchester Scar Scale [MSS]), and pain intensity (visual analog scale) were assessed at 1, 4, 12, and 24 weeks postoperatively. The difference in total "wound-closure cost" between the two groups was also analyzed.

RESULTS

There were no wound-related complications and no significant differences in SBSES or MSS scores between the two groups (P = 0.609 and P = 0.141, respectively). However, the staple group had significantly higher SBSES scores, compared to the suture group, at 24 wk postoperatively (4.06 ± 0.94 versus 3.26 ± 1.24; P = 0.030, respectively); MSS scores were significantly lower in the staple group than in the suture group at 24 wk postoperatively (6.72 ± 1.27 versus 8.16 ± 2.17, respectively; P = 0.028). Visual analog scale scores were significantly lower in the suture group than in the staple group (P = 0.038). The total wound-closure cost was significantly higher in the staple group than in the suture group (137.10 ± 8.39 versus 81.79 ± 19.95 USD; P < 0.001).

CONCLUSIONS

When dermal staples were used, wound complications were absent and long-term cosmetic outcomes were superior; however, pain intensity was higher and the cost was greater, although healing was significantly more rapid, compared to intradermal sutures. Closure using absorbable dermal staples may be safe and effective for cervical incisions during thyroid surgery. Further studies with larger number of participants are needed to confirm our findings.

Subcuticular sutures for skin closure in non-obstetric surgery

BACKGROUND

Following surgery, surgical wounds can be closed using a variety of devices including sutures (subcuticular or transdermal), staples and tissue adhesives. Subcuticular sutures are intradermal stitches (placed immediately below the epidermal layer). The increased availability of synthetic absorbable filaments (stitches which are absorbed by the body and do not have to be removed) has led to an increased use of subcuticular sutures. However, in non-obstetric surgery, there is still controversy about whether subcuticular sutures increase the incidence of wound complications.

OBJECTIVES

To examine the efficacy and acceptability of subcuticular sutures for skin closure in non-obstetric surgery.

SEARCH METHODS

In March 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

All randomised controlled trials which compared subcuticular sutures with any other methods for skin closure in non-obstetric surgery were included in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials, extracted data and carried out risk of bias and GRADE assessment of the certainty of the evidence.

MAIN RESULTS

We included 66 studies (7487 participants); 11 included trials had more than two arms. Most trials had poorly-reported methodology, meaning that it is unclear whether they were at high risk of bias. Most trials compared subcuticular sutures with transdermal sutures, skin staples or tissue adhesives. Most outcomes prespecified in the review protocol were reported. The certainty of evidence varied from high to very low in the comparisons of subcuticular sutures with transdermal sutures or staples and tissue adhesives; the certainty of the evidence for the comparison with surgical tapes and zippers was low to very low. Most evidence was downgraded for imprecision or risk of bias. Although the majority of studies enrolled people who underwent CDC class 1 (clean) surgeries, two-thirds of participants were enrolled in studies which included CDC class 2 to 4 surgeries, such as appendectomies and gastrointestinal surgeries. Most participants were adults in a hospital setting. Subcuticular sutures versus transdermal sutures There may be little difference in the incidence of SSI (risk ratio (RR) 1.10; 95% confidence interval (CI) 0.80 to 1.52; 3107 participants; low-certainty evidence). It is uncertain whether subcuticular sutures reduce wound complications (RR 0.83; 95% CI 0.40 to 1.71; 1489 participants; very low-certainty evidence). Subcuticular sutures probably improve patient satisfaction (score from 1 to 10) (at 30 days; MD 1.60, 95% CI 1.32 to 1.88; 290 participants; moderate-certainty evidence). Wound closure time is probably longer when subcuticular sutures are used (MD 5.81 minutes; 95% CI 5.13 to 6.49 minutes; 585 participants; moderate-certainty evidence). Subcuticular sutures versus skin staples There is moderate-certainty evidence that, when compared with skin staples, subcuticular sutures probably have little effect on SSI (RR 0.81, 95% CI 0.64 to 1.01; 4163 participants); but probably decrease the incidence of wound complications (RR 0.79, 95% CI 0.64 to 0.98; 2973 participants). Subcuticular sutures are associated with slightly higher patient satisfaction (score from 1 to 5) (MD 0.20, 95% CI 0.10 to 0.30; 1232 participants; high-certainty evidence). Wound closure time may also be longer compared with staples (MD 0.30 to 5.50 minutes; 1384 participants; low-certainty evidence). Subcuticular sutures versus tissue adhesives, surgical tapes and zippers There is moderate-certainty evidence showing no clear difference in the incidence of SSI between participants treated with subcuticular sutures and those treated with tissue adhesives (RR 0.77, 95% CI 0.41 to 1.45; 869 participants). There is also no clear difference in the incidence of wound complications (RR 0.62, 95% CI 0.35 to 1.11; 1058 participants; low-certainty evidence). Subcuticular sutures may also achieve lower patient satisfaction ratings (score from 1 to 10) (MD -2.05, 95% CI -3.05 to -1.05; 131 participants) (low-certainty evidence). In terms of SSI incidence, the evidence is uncertain when subcuticular sutures are compared with surgical tapes (RR 1.31, 95% CI 0.40 to 4.27; 354 participants; very low-certainty evidence) or surgical zippers (RR 0.80, 95% CI 0.08 to 8.48; 424 participants; very low-certainty evidence). There may be little difference in the incidence of wound complications between participants treated with subcuticular sutures and those treated with surgical tapes (RR 0.90, 95% CI 0.61 to 1.34; 492 participants; low-certainty evidence). It is uncertain whether subcuticular sutures reduce the risk of wound complications compared with surgical zippers (RR 0.55, 95% CI 0.15 to 2.04; 424 participants; very low-certainty evidence). It is also uncertain whether it takes longer to close a wound with subcuticular sutures compared with tissue adhesives (MD -0.34 to 10.39 minutes; 895 participants), surgical tapes (MD 0.74 to 6.36 minutes; 169 participants) or zippers (MD 4.38 to 8.25 minutes; 424 participants) (very low-certainty evidence). No study reported results for patient satisfaction compared with surgical tapes or zippers.

AUTHORS' CONCLUSIONS

There is no clear difference in the incidence of SSI for subcuticular sutures in comparison with any other skin closure methods. Subcuticular sutures probably reduce wound complications compared with staples, and probably improve patient satisfaction compared with transdermal sutures or staples. However, tissue adhesives may improve patient satisfaction compared with subcuticular sutures, and transdermal sutures and skin staples may be quicker to apply than subcuticular sutures. The quality of the evidence ranged from high to very low; evidence for almost all comparisons was subject to some limitations. There seems to be no need for additional new trials to explore the comparison with staples because there are high-quality studies with large sample sizes and some ongoing studies. However, there is a need for studies exploring the comparisons with transdermal sutures, tissue adhesives, tapes and zippers, with high-quality studies and large sample sizes, including long-term assessments.

Multi-Layered Polyamide/Collagen Scaffolds with Topical Sustained Release of N-Acetylcysteine for Promoting Wound Healing

Background

Impaired wound healing might be associated with many issues, especially overactive of reactive oxygen species (ROS), deficiency of blood vessels and immature of epidermis. N-acetylcysteine (NAC), as an antioxidant, could solve these problems by inhibiting overreactive of ROS, promoting revascularization and accelerating re-epithelialization. How to deliver NAC in situ with a controllable releasing speed still remain a challenge.

Materials and Methods

In this study, we combined collagen (Col) with N-acetylcysteine to perform the characteristics of sustained release and chemically crosslinked Col/NAC composite with polyamide (PA) nanofibers to enhance the mechanical property of collagen and fabricated this multi-layered scaffold (PA-Col/NAC scaffold). The physical properties of the scaffolds such as surface characteristics, water absorption and tensile modulus were tested. Meanwhile, the ability to promote wound healing in vitro and in vivo were investigated.

Results

These scaffolds were porous and performed great water absorption. The PA-Col/NAC scaffold could sustainably release NAC for at least 14 days. After cell implantation, PA-Col/NAC scaffold showed better cell proliferation and cell migration than the other groups. In vivo, PA-Col/NAC scaffolds could promote wound healing best among all the groups.

Conclusion

The multi-layered scaffolds could obviously accelerate the process of wound healing and exert better and prolonged effects.

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.

Tensile properties of synthetic, absorbable monofilament suture materials before and after incubation in phosphate-buffered saline

OBJECTIVE

To compare tensile properties of synthetic, absorbable, monofilament suture material before and after incubation in phosphate-buffered saline (PBS).

STUDY DESIGN

Two sizes (2-0 and 3-0) of Biosyn, Maxon, Monocryl, PDS II, Securocryl, and Securodox were tested.

SAMPLE POPULATION

Ten suture loops per group.

METHODS

Tensile strength, elongation, and modulus of suture loops were measured at baseline and after 7, 14, 21, or 28 days of incubation in PBS.

RESULTS

Size, suture material, and size × suture material interaction influenced maximum breaking load, maximum elongation, and modulus of elasticity. At baseline, 2-0 and 3-0 Maxon had the highest breaking loads (111.67 N and 79.71 N, respectively) for their size, and 2-0 PDSII and 3-0 Securodox had the lowest (68.71 N and 48.73 N, respectively). Maxon 2-0 and 3-0 had the greatest elongations (9.68 mm and 8.45 mm, respectively) for their size, and 2-0 Biosyn and 3-0 Securocryl had the least (7.21 mm and 6.58 mm, respectively). Biosyn 2-0 and 3-0 had the highest modulus. With incubation, Maxon (2-0), PDS II (2-0, 3-0), and Securodox (2-0, 3-0) maintained or gained strength over 4 weeks. Strengths of 2-0 and 3-0 Biosyn and 3-0 Maxon were maintained for 2 weeks, while Monocryl and Securocryl lost 20% to 44% of baseline strength within 1 week and 60% to 72% within 2 weeks. Day 7 strengths of 2-0 Biosyn and 2-0 Monocryl were greater than baseline strength of 2-0 PDS II. Strength of 3-0 Biosyn at day 14 was greater than strength of Monocryl at days 7 and 14 and greater than strength of 3-0 PDS II, 3-0 Securodox, and 3-0 Securocryl at baseline and days 7 and 14.

CONCLUSION

Suture tensile properties varied with suture size, composition, and brand. At baseline, Maxon suture had the greatest strength and elongation, and Biosyn had the greatest stiffness.

CLINICAL SIGNIFICANCE

Tensile strength retention, when reported as a percentage of original strength, provides insufficient information for comparison of suture tensile properties.

Natural fiber reinforced biodegradable staples: Novel approach for efficient wound closure

Every year millions of lacerations and incisions taken place and require an effective methodology to manage the wound for a better life. The primary causes include mechanical trauma and surgical procedures. The rapid healing of the wound is critical to prevent further infection and reduction pain etc. Current options comprise of sutures, staplers, surgical strips and glues, again the intervention depends on the type of wound and the surgeon preference. The current wound closure techniques pose various potent limitations and confronting the problems to create a desired wound closure technique is necessary for faster and effective wound healing management. The surgical staplers are fast and easy to use wound closure devices, which approximates the edges of the wounds together by staples. The staples are mostly made up of metals like titanium and stainless steel. By modifying the existing stapling method using biodegradable staples that are expected to have good mechanical properties, not require removal procedure, minimized scarring and an overall acceleration in wound healing with minimal complications. Present, the paper focuses on the novel hypothesis on natural fiber reinforced biodegradable polymer staples as wound enclosures with high strength and degradability.

Biostimulatory effects of polydioxanone, poly-d, l lactic acid, and polycaprolactone fillers in mouse model

BACKGROUND

Numerous fillers are increasingly used for augmentation of volume loss and relaxation of facial wrinkles. Collagen stimulators are the latest next-generation dermal fillers that can induce neocollagenesis. To investigate biophysical characteristics, safety, and efficacy of newly developed polydioxanone (PDO) filler in comparison with poly-l lactic acid (PLLA) and polycaprolactone (PCL) fillers.

METHODS

In vitro assay, morphology of particles, and rheological property of fillers were measured. A total of 24 female hairless mice (SKH1-Hr^hr ) were randomly divided into three groups and injected with PDO, PLLA, or PCL fillers. Durability of fillers was assessed at 0, 3 days, and 1, 4, 8, 12 weeks after injection using folliscope and PRIMOS. To determine biocompatibility and neocollagenesis, histologic evaluation was performed at 1, 4, 8, and 12 weeks after injection. Efficacy was also evaluated based on skin surface roughness changes using PRIMOS in a hairless mouse photoaging model.

RESULTS

In the particle morphology test, PDO microspheres had an irregular surface and were spherical and uniformly sized. PDO filler demonstrated similar neocollagenesis and inflammatory response to other collagen stimulators. PDO filler showed better biodegradability than PLLA and PCL fillers. In the hairless mouse photoaging model, there was a statistically significant decrease in skin surface roughness after PDO filler injection.

CONCLUSIONS

Our data suggest that newly developed collagen stimulating PDO filler might be a safe and effective option for correction of volume loss and rejuvenation of photoaging skin.

Optimal biomaterials for tracheal epithelial grafts: An in vitro systematic comparative analysis

Tracheal injury, stenosis, and malignancy demand tracheal reconstruction, which often fails due to the lack of a functioning epithelium. We performed an extensive comparative analysis to determine optimal biomaterials for developing tracheal epithelial grafts with mucociliary function. We screened Hyaluronan-Poly(Ethylene Glycol), Chitosan-Collagen, Collagen Vitrigel Membrane, Fibrin Glue, Silk Fibroin, and Gelatin based on various parameters including mechanical strength, bulk degradation, cell attachment, spreading, metabolic activity, focal adhesion formation, and differentiation into ciliated and goblet cells. Silk Fibroin had significantly higher tensile strength (21.23 ± 4.42 MPa), retained 50% of its mass across 5 weeks, allowed 80-100% cell spreading and increasing metabolic activity across 10 days, focal adhesion formation within 2 h, and differentiation into 5.9 ± 2.6% goblet cells. Silk Fibroin, however, led to poor ciliation, producing 5.5 ± 3.9% ciliated cells, whereas Collagen Vitrigel Membrane promoted excellent ciliation. To capitalize on the mechanical and differentiation benefits of its respective components, we developed a composite biomaterial of Silk Fibroin and Collagen Vitrigel Membrane (SF-CVM), which demonstrated enhanced maturation into 20.6 ± 1.7% ciliated and 5.6 ± 1.0% goblet cells. Development of biomaterials-based airway epithelial grafts that provide desirable mechanics and differentiation is a major step towards treatment of airway disease. STATEMENT OF SIGNIFICANCE: Tracheal blockage, injury, and malignancy greater than 50% of the adult tracheal length cannot be safely resected. Tracheal replacement is one approach, but a major cause of transplant failure is the lack of a functioning epithelium. While tissue engineering for tracheal regeneration using biomaterials is promising, there is currently no gold standard. Therefore, we performed a systematic comparative study to characterize relevant materials for generating a biomaterials-based airway epithelial graft. We developed a composite biomaterial intended for surgical implantation providing tensile strength, slow biodegradation, and optimal support for differentiation of mature epithelia. This is a significant step augmenting current state-of-the-art methods for airway surgeries, laryngeal reconstruction, and tracheal tissue engineering.

A comparative study of immediate wound healing complications following cleft lip repair using either absorbable or non-absorbable skin sutures

Objectives

The aim of the study was to compare wound healing complications following the use of either absorbable or non-absorbable sutures for skin closure in cleft lip repair.

Materials and Methods

This was a randomized controlled trial conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Idi Araba, Lagos State, Nigeria. Sixty subjects who required either primary or secondary cleft lip repair and satisfied all the inclusion criteria were recruited and randomized into two groups (Vicryl group or Nylon group). The surgical wounds in all subjects were examined on 3rd, 7th, and 14th postoperative days (POD) for presence or absence of tissue reactivity, wound dehiscence, and local wound infection.

Results

Hemorrhage, tissue reactivity, wound dehiscence, and local wound infection were identified as wound healing complications following cleft lip repair. The incidence of postoperative wound healing complications on POD3 was 33.3%. Tissue reactivity was more common throughout the evaluation period with the use of an absorbable (Vicryl) suture compared to a non-absorbable (Nylon) suture, although the difference was statistically significant only on POD7 (P=0.002). There were no significant differences in the incidences of wound dehiscence and infection between the two groups throughout the observation period.

Conclusion

There were no statistically significant differences in the incidences of wound dehiscence and surgical site wound infection following the use of either Vicryl or Nylon for skin closure during cleft lip repair. However, more cases of tissue reactivity were recorded in the Vicryl group than in the Nylon group on POD7. Particular attention must be paid to detect the occurrence of wound healing complications, most especially tissue reactivity, whenever a Vicryl suture is used for skin closure in cleft lip repair.

Inorganic Nanomaterials for Soft Tissue Repair and Regeneration

Inorganic nanomaterials have witnessed significant advances in areas of medicine including cancer therapy, imaging, and drug delivery, but their use in soft tissue repair and regeneration is in its infancy. Metallic, ceramic, and carbon allotrope nanoparticles have shown promise in facilitating tissue repair and regeneration. Inorganic nanomaterials have been employed to improve stem cell engraftment in cellular therapy, material mechanical stability in tissue repair, electrical conductivity in nerve and cardiac regeneration, adhesion strength in tissue approximation, and antibacterial capacity in wound dressings. These nanomaterials have also been used to improve or replace common surgical materials and restore functionality to damaged tissue. We provide a comprehensive overview of inorganic nanomaterials in tissue repair and regeneration, and discuss their promise and limitations for eventual translation to the clinic.

Spatiotemporal modeling of laser tissue soldering using photothermal nanocomposites

OBJECTIVE

Laser tissue soldering using photothermal solders is a technology that facilitates rapid sealing using heat-induced changes in the tissue and the solder material. The solder material is made of gold nanorods embedded in a protein matrix patch that can be placed over the tissue rupture site and heated with a laser. Although laser tissue soldering is an attractive approach for surgical repair, potential photothermal damage can limit the success of this approach. Development of predictive mathematical models of photothermal effects including cell death, can lead to more efficient approaches in laser-based tissue repair.

METHODS

We describe an experimental and modeling investigation into photothermal solder patches for sealing porcine and mouse cadaver intestine sections using near-infrared laser irradiation. Spatiotemporal changes in temperature were determined at the surface as well as various depths below the patch. A mathematical model, based on the finite element method, predicts the spatiotemporal temperature distribution in the patch and surrounding tissue, as well as concomitant cell death in the tissue is described.

RESULTS

For both the porcine and mouse intestine systems, the model predicts temperatures that are quantitatively similar to the experimental measurements with the model predictions of temperature increase often being within a just a few degrees of experimental measurements.

CONCLUSION

This mathematical model can be employed to identify optimal conditions for minimizing healthy cell death while still achieving a strong seal of the ruptured tissue using laser soldering. Lasers Surg. Med. 50:143-152, 2018. © 2017 Wiley Periodicals, Inc.

Poly(Lactic Acid) Blends with Poly(Trimethylene Carbonate) as Biodegradable Medical Adhesive Material

A novel medical adhesive was prepared by blending poly(lactic acid) (PLA) with poly(trimethylene carbonate) (PTMC) in ethyl acetate, and the two materials were proven to be biodegradable and biocompatible. The medical adhesive was characterized by ¹H nuclear magnetic resonance (¹HNMR), gel permeation chromatography (GPC), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The water vapor transmission rate (WVTR) of this material was measured to be 7.13 g·cm⁻²·24 h⁻¹. Its degree of comfortability was confirmed by the extensibility (E) and the permanent set (PS), which were approximately 7.83 N·cm⁻² and 18.83%, respectively. In vivo tests regarding rabbit immunoglobulin M (IgM), rabbit immunoglobulin G (IgG), rabbit bone alkaline phosphatase (BALP), rabbit interleukin 6 (IL-6), rabbit interleukin 10 (IL-10), rabbit tumor necrosis factor α(TNFα), glutamic-oxaloacetic transaminase (AST/GOT), glutamic-pyruvic transaminase (ALT/GPT), alkaline phosphatase (AKP), blood urea nitrogen (BUN) and creatinine (Cr) indicated that the PLA-PTMC medical adhesive was not harmful to the liver and kidneys. Finally, pathological sections indicated that PLA-PTMC was more effective than the control group. These data suggest that in addition to having a positive effect on hemostasis and no sensibility to wounds, PLA-PTMC can efficiently prevent infections and has great potential as a medical adhesive.