Monocryl suture, a new ultra-pliable absorbable monofilament suture

Fibro-porous poliglecaprone/polycaprolactone conduits: synergistic effect of composition and in vitro degradation on mechanical properties

Blends of poliglecaprone (PGC) and polycaprolactone (PCL) of varying compositions were electrospun into tubular conduits and their mechanical, morphological, thermal and in vitro degradation properties were evaluated under simulated physiological conditions. Generally, mechanical strength, modulus and hydrophilic nature were enhanced by the addition of PGC to PCL. An in vitro degradation study in phosphate-buffered saline (pH 7.3) was carried out for up to 1 month to understand the hydrolytic degradation effect on the mechanical properties in both the longitudinal and circumferential directions. Pure PCL and 4:1 PCL/PGC blend scaffolds exhibited considerable elastic stiffening after a 1 month in vitro degradation. Fourier transform infrared spectroscopic and DSC techniques were used to understand the degradation behavior and the changes in structure and crystallinity of the polymeric blends. A 3:1 PCL/PGC blend was concluded to be a judicious blend composition for tubular grafts based on overall results on the mechanical properties and performance after a 1 month in vitro degradation study.

Function of mechanically lengthened jejunum after restoration into continuity

PURPOSE

Distraction enterogenesis is a potential treatment for patients with short bowel syndrome. We previously demonstrated successful lengthening of jejunum using a degradable spring device in rats. Absorptive function of the lengthened jejunum after restoration into intestinal continuity needs to be determined.

METHODS

Encapsulated polycaprolactone springs were placed into isolated jejunal segments in rats for four weeks. Lengthened segments of jejunum were subsequently restored into intestinal continuity. Absorption studies were performed by placing a mixture of a non-absorbable substrate and glucose into the lumen of the restored jejunum.

RESULTS

Restored jejunal segments demonstrated visible peristalsis at specimen retrieval. Compared to normal jejunal controls, restored segments demonstrated equal water absorption and greater glucose absorption. Restored segments had thicker smooth muscle, increased villus height, increased crypt depth, and decreased sucrase activity compared to normal jejunum. The density of enteric ganglia increased after restoration to near normal levels in the submucosa and to normal levels in the myenteric plexus.

CONCLUSION

Jejunum lengthened with a degradable device demonstrates peristaltic and enzymatic activity as well as glucose and water absorption after restoration into intestinal continuity. Our findings further demonstrate the therapeutic potential of a degradable device.

Superficial wound closure complications with barbed sutures following knee arthroplasty

As quality measures may be increasingly used in knee surgery reimbursement, an important focus in outcome assessment will shift toward minimizing complications and increasing efficiency in knee arthroplasty reconstruction. The purpose of this study was to evaluate the efficacy of barbed, absorbable sutures in closure of the longitudinal surgical incision following knee arthroplasty, using post-operative complication occurrences. In 416 operations, primary outcomes assessed were deep infection, superficial infection, dehiscence, or stitch abscesses. Secondary outcomes included self-limiting eschar, severe effusion, arthrofibrosis, and keloid formation. Evaluation of overall primary outcomes showed a higher rate of wound complications using barbed sutures (P < 0.001). With increased rates of infection and overall closure related complications, this study shows that barbed suture use for superficial closure after knee arthroplasty should be avoided.

Increased Adipogenic and Decreased Chondrogenic Differentiation of Adipose Derived Stem Cells on Nanowire Surfaces

Despite many advances in tissue engineering, there are still significant challenges associated with restructuring, repairing, or replacing damaged tissue in the body. Currently, a major obstacle has been trying to develop a scaffold for cartilage tissue engineering that provides the correct mechanical properties to endure the loads associated with articular joints as well as promote cell-scaffold interactions to aid in extracellular matrix deposition. In addition, adipogenic tissue engineering is widely growing due to an increased need for more innovative reconstructive therapies following adipose tissue traumas and cosmetic surgeries. Recently, lipoaspirate tissue has been identified as a viable alternative source for mesenchymal stem cells because it contains a supportive stroma that can easily be isolated. Adipose derived stem cells (ADSCs) can differentiate into a variety of mesodermal lineages including the adipogenic and chondrogenic phenotypes. Biodegradable polymeric scaffolds have been shown to be a promising alternative and stem cells have been widely used to evaluate the compatibility, viability, and bioactivity of these materials. Polycaprolactone is a bioresorbable polymer, which has been widely used for biomedical and tissue engineering applications. The fundamental concept behind successful synthetic tissue-engineered scaffolds is to promote progenitor cell migration, adhesion, proliferation, and induce differentiation, extracellular matrix synthesis, and finally integration with host tissue. In this study, we investigated the adhesion, proliferation, and chondrogenic and adipogenic differentiation of ADSCs on nanowire surfaces. A solvent-free gravimetric template technique was used to fabricate polycaprolactone nanowires surfaces. The results indicated that during the growth period i.e., initial 7 days of culture, the nanowire surfaces (NW) supported adhesion and proliferation of the cells that had elongated morphologies. However, cell on surfaces without nanowires had non-elongated morphologies. Further, immunofluorescence imaging of marker proteins showed that the nanowires surfaces did not appear to support chondrogenic differentiation whereas supported adipogenic differentiation of ADSCs.

A porous tissue engineering scaffold selectively degraded by cell-generated reactive oxygen species

Biodegradable tissue engineering scaffolds are commonly fabricated from poly(lactide-co-glycolide) (PLGA) or similar polyesters that degrade by hydrolysis. PLGA hydrolysis generates acidic breakdown products that trigger an accelerated, autocatalytic degradation mechanism that can create mismatched rates of biomaterial breakdown and tissue formation. Reactive oxygen species (ROS) are key mediators of cell function in both health and disease, especially at sites of inflammation and tissue healing, and induction of inflammation and ROS are natural components of the in vivo response to biomaterial implantation. Thus, polymeric biomaterials that are selectively degraded by cell-generated ROS may have potential for creating tissue engineering scaffolds with better matched rates of tissue in-growth and cell-mediated scaffold biodegradation. To explore this approach, a series of poly(thioketal) (PTK) urethane (PTK-UR) biomaterial scaffolds were synthesized that degrade specifically by an ROS-dependent mechanism. PTK-UR scaffolds had significantly higher compressive moduli than analogous poly(ester urethane) (PEUR) scaffolds formed from hydrolytically-degradable ester-based diols (p < 0.05). Unlike PEUR scaffolds, the PTK-UR scaffolds were stable under aqueous conditions out to 25 weeks but were selectively degraded by ROS, indicating that their biodegradation would be exclusively cell-mediated. The in vitro oxidative degradation rates of the PTK-URs followed first-order degradation kinetics, were significantly dependent on PTK composition (p < 0.05), and correlated to ROS concentration. In subcutaneous rat wounds, PTK-UR scaffolds supported cellular infiltration and granulation tissue formation, followed first-order degradation kinetics over 7 weeks, and produced significantly greater stenting of subcutaneous wounds compared to PEUR scaffolds. These combined results indicate that ROS-degradable PTK-UR tissue engineering scaffolds have significant advantages over analogous polyester-based biomaterials and provide a robust, cell-degradable substrate for guiding new tissue formation.

A novel biodegradable device for intestinal lengthening

PURPOSE

Previous studies demonstrated successful mechanical lengthening of rat jejunum using an encapsulated Nitinol spring device over a stabilizing guidewire. We sought to improve the applicability of intestinal lengthening by creating a biodegradable device.

METHODS

Using properties of the Nitinol spring device, polycaprolactone (PCL) springs with similar outer diameter and spring constant were created. After in vitro testing in dry and hydrated environments, they were used to lengthen 1-cm isolated segments of rat jejunum in vivo. Retrieved segments were analyzed histologically.

RESULTS

Optimal PCL spring devices had an average spring constant 1.8 ± 0.4 N/m, pitch 1.55 ± 0.85 mm, and band width 0.825 ± 0.016 mm. In vitro testing demonstrated stable spring constants. Jejunal segments were lengthened from 1.0 cm to 2.7 ± 0.4 cm without needing a stabilizing guidewire. Histology demonstrated increased smooth muscle thickness and fewer ganglia compared to controls. Lengthened jejunum was successfully restored into intestinal continuity and demonstrated peristalsis under fluoroscopy.

CONCLUSIONS

A novel biodegradable spring device was successfully created and used to mechanically lengthen intestinal segments. Use of a biodegradable device may obviate the need for retrieval after lengthening. This improves device applicability and may be useful for the treatment of short bowel syndrome.

Control of hyperbranched structure of polycaprolactone/poly(ethylene glycol) polyurethane block copolymers by glycerol and their hydrogels for potential cell delivery

A series of biodegradable amphiphilic polyurethane block copolymers with hyperbranched structure were synthesized by copolymerizing poly(ε-caprolactone) (PCL) and poly(ethylene glycol) (PEG) together with glycerol. The copolymers were characterized, and their composition and branch length were varied with the feeding ratio between PCL, PEG, and glycerol used. Hydrogels were formed from these copolymers by swelling of water at low polymer concentrations. The hydrogels were thixotropic, and their dynamic viscoelastic properties were dependent on the copolymer composition, branch length, and polymer concentration. Hydrolytic degradation of the hydrogels was evaluated by mass loss and changes in molecular structures. The porous morphology of the hydrogels provided good permeability for gas and nutrition. Together with the tunable rheological properties, the hydrogels were found to be suitable for 3D living cell encapsulation and delivery. The morphology of the solid copolymers was semicrystalline, while the hydrogels were totally amorphous without crystallinity, providing a mild aqueous environment for living cells. When the encapsulated cells were recovered from the hydrogels followed by subculture, they showed good cell viability and proliferation ability. The results indicate that the hyperbranched copolymers hydrogels developed in this work may be promising candidates for potential injectable cell delivery application.

Comparison of poliglecaprone-25 and polyglactin-910 in cutaneous surgery

BACKGROUND

Few clinical studies have compared deep absorbable sutures. Poliglecaprone-25 and polyglactin-910 are two of the most commonly used absorbable sutures in cutaneous surgery.

OBJECTIVES

To compare the rate of suture extrusion, degree of lumpiness, and appearance of scars from wounds closed with poliglecaprone-25 and polyglactin-910.

METHODS

Poliglecaprone-25 or polyglactin-910 was used for closure of the deep part of Mohs defects. The number of extruded sutures and the number of lumps were recorded at each follow-up visit. Photographs of 1-week and 3-month postoperative scars were rated on a visual analogue scale.

RESULTS

One hundred forty patients completed the study. There was a statistically significant difference in the percentage of extruded sutures between poliglecaprone-25 (3.1%) and polyglactin-910 (11.4%) (p < .01). There was not a statistically significant difference in the percentage of lumps (both 22%) or overall appearance of scars at 1 week or 3 months.

CONCLUSION

Poliglecaprone-25 resulted in significantly less extruded sutures than did polyglactin-910, although both resulted in the same degree of lumpiness and similar-appearing scars at 1 week and 3 months.

Effects of Hot-drawing and Annealing on the Morphology and Mechanical Properties of Biodegradable Polyester Monofilament Fibers

Co/terpolymers of L-lactide (LL), ∊-caprolactone (CL) and glycolide (G) are biodegradable in the human body and, as such, have considerable potential for use in biomedical applications such as absorbable surgical sutures, nerve guides, bone fixation devices and drug delivery systems. This study focuses its attention on their potential as monofilament fibers for absorbable suture applications. Random co/terpolymers with different compositions of LL, CL and G were synthesized via bulk ring-opening polymerization. The polymers obtained were melt spun at slow speeds into ice-cooled water to produce as-spun monofilament fibers with as little molecular orientation and crystallinity as possible. Combinations of off-line hot-drawing and annealing steps under controlled conditions of draw rate, draw ratio, temperature and time were then employed in order to develop the fiber's oriented semi-crystalline morphology. The mechanical properties of the fibers were tested after each processing step and compared. The tensile test results showed that the tensile strength was strongly dependent on the draw ratio. A high draw ratio was obtained by multiple off-line hot-drawings with intermediate annealing. The first hot-drawing step dramatically enhanced the mechanical properties relative to those of the weak, highly extensible as-spun fiber. Subsequent annealing at a suitable temperature and for an appropriate length of time increased fiber flexibility as a result of molecular relaxation. Additional hot-drawing steps, again under precise temperature-time conditions, increased the total draw ratio and further enhanced the fiber's mechanical strength.

Estudo comparativo entre os fios de algodão, poliglactina e poliglecaprone nas anastomoses intestinais de cães

RACIONAL: Nos últimos anos muitos fios de sutura foram desenvolvidos e depois abandonados. Até hoje não foi encontrado um fio cirúrgico ideal aos intestinos ou a outros tecidos de um modo geral, tornando sua escolha tarefa difícil. OBJETIVO: Avaliar macro e microscopicamente a cicatrização de anastomoses do intestino delgado de cães, utilizando suturas com fios de poliglecaprone 25; poliglactina 910 e algodão. MÉTODOS: Vinte cães machos adultos foram operados e submetidos a três anastomoses no intestino delgado empregando a técnica extramucosa com pontos separados. Foram utilizados os três tipos fios e as anastomoses foram analisadas em diferentes períodos no pós-operatório: grupo I -três dias; grupo II - sete dias; grupo III - 14 dias; grupo IV - 21dias. A análise macroscópica consistiu em avaliar a presença ou não de peritonite, aspecto das anastomoses e aderências. Os estudos histológicos das anastomoses, empregando a hematoxilina e eosina e o tricrômico de Masson analisaram a inflamação exsudativa, inflamação granulomatosa, o revestimento epitelial da mucosa e as fibras colágenas. RESULTADOS: Na avaliação macroscópica os fios apresentaram boa coaptação das bordas com moderado grau de aderência entre alças e omento do 3º ao 21º dia do pós-operatório. A avaliação microscópica mostrou inflamação exsudativa com neutrófilos e fibrina que variou de discreta a moderada até o 14º dia; inflamação granulomatosa com presença de macrófagos, células gigantes multinucleadas e células epitelioides mais evidentes ao 14º dia para o fio algodão; presença de tecido de granulação (fibroblastos) e fibras colágenas, de forma moderada, a partir do 7º dia para os três fios. CONCLUSÃO: Os três tipos de fios de sutura apresentaram comportamento semelhante, com boa cicatrização e podem ser recomendados em anastomoses do intestino delgado.

Mechano-morphological studies of aligned nanofibrous scaffolds of polycaprolactone fabricated by electrospinning

Mechanical and morphological studies of aligned nanofibrous meshes of poly(epsilon-caprolactone) (PCL) fabricated by electrospinning at different collector rotation speeds (0, 3000 and 6000 rpm) for application as bone tissue scaffolds are reported. SEM, XRD and DSC analyses were used for the morphological characterization of the nanofibers. Scaffolds have a nanofibrous morphology with fibers (majority) having a diameter in the range of 550-350 nm (depending on fiber uptake rates) and an interconnected pore structure. With the increase of collector rotation speed, the nanofibers become more aligned and oriented perpendicular to the axis of rotation. Deposition of fibers at higher fiber collection speeds has a profound effect on the morphology and mechanical properties of individual fibers and also the bulk fibrous meshes. Nanoindentation was used for the measurement of nanoscopic mechanical properties of individual fibers of the scaffolds. The hardness and Young's modulus of aligned fibers measured by nanoindentation decreased with collector rotation speeds. This reveals the difference in the local microscopic structure of the fibers deposited at higher speeds. The sequence of nanoscopic mechanical properties (hardness and modulus) of three fibers is PCL at 0 rpm > PCL at 3000 rpm > PCL at 6000 rpm. This may be explained due to the decrease in crystallinity of fibers at higher uptake rates. However, uni-axial tensile properties of (bulk) scaffolds (tensile strength and modulus) increased with increasing collector rotation speed. The average ultimate tensile strength of scaffolds (along the fiber alignment) increased from 2.21 +/- 0.23 MPa for PCL at uptake rate of zero rpm, to a value of 4.21 +/- 0.35 MPa for PCL at uptake rate of 3000 rpm and finally to 9.58 +/- 0.71 MPa for PCL at 6000 rpm. Similarly, the tensile modulus increased gradually from 6.12 +/- 0.8 MPa for PCL at uptake rate of zero rpm, to 11.93 +/- 1.22 MPa for PCL at uptake rate of 3000 rpm and to 33.20 +/- 1.98 MPa for PCL at 6000 rpm. The sequence of macroscopic mechanical properties (tensile strength and modulus) of three fibers, from highest to lowest, is PCL at 0 rpm < PCL at 3000 rpm < PCL at 6000 rpm. This is attributed to the increased fiber alignment and packing and decrease in inter-fiber pore size at higher uptake rates.

Synergistic effect of scaffold composition and dynamic culturing environment in multilayered systems for bone tissue engineering

Bone extracellular matrix (ECM) is composed of mineralized collagen fibrils which support biological apatite nucleation that participates in bone outstanding properties. Understanding and mimicking bone morphological and physiological parameters at a biological scale is a major challenge in tissue engineering scaffolding. Using emergent (nano)technologies scaffold designing may be critically improved, enabling highly functional tissue substitutes for bone applications. This study aims to develop novel biodegradable composite scaffolds of tricalcium phosphate (TCPs) and electrospun nanofibers of poly(ϵ-caprolactone) (PCL), combining TCPs osteoconductivity with PCL biocompatibility and elasticity, mimicking bone structure and composition. We hypothesized that scaffolds with such structure/composition would stimulate the proliferation and differentiation of bone marrow stromal cells (BMSCs) towards the osteogenic phenotype. Composite scaffolds, developed by electrospining using consecutive stacked layers of PCL and TCPs, were characterized by FTIR spectroscopy, X-Ray diffraction and scanning electronic microscopy. Cellular behavior was assessed in goat BMSCs seeded onto composite scaffolds and cultured in static or dynamic conditions, using basal or osteogenic media during 7, 14 or 21 days. Cellular proliferation was quantified and osteogenic differentiation confirmed by alkaline phosphatase activity, alizarin red staining and immunocytochemistry for osteocalcin and collagen I. Results suggest that PCL-TCP scaffolds provide a 3D support for gBMSCs proliferation and osteogenic differentiation with production of ECM. TCPs positively stimulate the osteogenic process, especially under dynamic conditions, where PCL-TCP scaffolds are sufficient to promote osteogenic differentiation even in basal medium conditions. The enhancement of the osteogenic potential in dynamic conditions evidences the synergistic effect of scaffold composition and dynamic stimulation in gBMSCs osteogenic differentiation.

Cecorraphy in single layer using polypropylene and poliglecaprone 25 threads: comparative study in rats

PURPOSE: To compare sutures with polypropylene and poliglecaprone 25 after partial cecotomy in rats. METHODS: Thirty six rats divided into two groups, A and B, of 18 animals; each group was also divided into three subgroups of six animals sacrificed at 4th, 7th and 14th days after surgery. Were studied the mortality, morbidity, complications attributable to sutures, macroscopy, optical microscopy and measurement of hydroxyproline at the level of the suture. RESULTS: There were no deaths or wound complications such as hematoma, seroma, abscess, evisceration or eventration. On microscopic evaluation reepithelization, coaptation and inflammation in both groups did not differ significantly. The average rate of tissue hydroxyproline found in the samples on the 4th day after surgery, was 21.38 mg/g tissue for group A and 16.68 mg/g for group B; on day 7 after surgery, the average was 15.64 mg/g tissue for group A and 26.53 mg/g for group B; on day 14, the average was 8.09 mg/g tissue for group A and 25.07 mg/g for group B. CONCLUSION: There were no differences on clinical evolution, macroscopic aspect, microscopic data and hydroxyproline concentration on both sutures.

MonoMax Suture: A New Long-Term Absorbable Monofilament Suture Made from Poly-4-Hydroxybutyrate

A long-term absorbable monofilament suture was developed using poly-4-hydroxybutyrate (P4HB) made from a biosynthetically produced homopolymer of the natural metabolite 4-hydroxybutyrate. The suture, called MonoMax, has prolonged strength retention. At 12 weeks, a size 3-0 MonoMax suture retains approximately 50% of its initial tensile strengthin vivoand is substantially degraded in one year with minimal tissue reaction. In contrast, PDS II monofilament suture (Ethicon, Inc., Somerville, NJ) has no residual strengthin vivoafter 12 weeks.In vivo, the MonoMax suture is hydrolyzed primarily by bulk hydrolysis, and is then degraded via the Krebs cycle. MonoMax is substantially more compliant than other monofilament sutures, and incorporates an element of elasticity. Its tensile modulus of 0.48 GPa is approximately one-third of the value of the PDS II fiber providing an exceptionally flexible and pliable fiber with excellent knot strength and security. These features are further enhanced by the fiber's elasticity, which also improves knot security and may help prevent wound dehiscence. Because of its performance advantages, this suture may find clinical utility in applications where prolonged strength retention, and greater flexibility are required, particularly in procedures like abdominal wall closure where wound dehiscence is still a significant post-surgical complication.

Biodegradation, biocompatibility, and drug delivery in poly(ω-pentadecalactone-co-p-dioxanone) copolyesters

Poly(ω-pentadecalactone-co-p-dioxanone) [poly(PDL-co-DO)] copolyesters are copolymers of an isodimorphic system, which remain semicrystalline over the whole range of compositions. Here, we evaluated enzymatically synthesized poly(PDL-co-DO) copolymers as new materials for biomedical applications. In vivo experiments using mice, showed that the copolyesters are well tolerated, with tissue responses that are comparable to poly(p-dioxanone). In addition, the copolymers were found to degrade hydrolytically at controlled rates over a period of several months under physiological conditions. The poly(PDL-co-DO) copolymers with up to 69 mol% DO units were successfully transformed to free-standing nanoparticles that are capable of encapsulating an anticancer drug, doxorubicin, or a polynucleotide, siRNA. Drug- or siRNA-loaded nanoparticles exhibited controlled and continuous release of agent over many weeks. In addition, siLUC-encapsulated poly(PDL-co-DO) nanoparticles were active in inhibiting luciferase gene expression in LUC-RKO cells. Because of substantial differences in structure and hydrophobicity between PDL and DO units, poly(PDL-co-DO) biodegradation rate and physical properties can be tuned over a wide range depending on the copolymer composition. Our results demonstrate that the semicrystalline and biodegradable poly(PDL-co-DO) copolyesters are promising biomaterials to serve as drug carriers, as well as potential raw materials for constructing bioabsorbable sutures and other medical devices.

Novel Bioactive Poly(ε-caprolactone)-Gelatin-Hydroxyapatite Nanocomposite Scaffolds for Bone Regeneration

Today, porous nanocomposite scaffolds play a key role in tissue engineering approaches and new processing methods and materials are constantly being developed to cater for the wide range of specifications and requirements. In addition, providing a structural support while maintaining bioactivity is one of the most important goals for these scaffolds, i.e. applying bioceramic into polymeric structures, facilitating the formation of functional tissues. In the last few years, hydroxyapatite (HAp) has been widely investigated as scaffolding material, mainly for its ability to bond to both hard and soft tissues. In this research, new bioactive scaffolds were successfully developed using poly(ε-caprolactone) (PCL), cross-linked gelatin and nanoparticles of HAp. After synthesis of nano HAp powder via chemical precipitation technique, the nanocomposites were prepared through layer solvent casting and lamination techniques. According to the obtained results, the amount of ultimate stress, stiffness and elastic modulus increased by addition of PCL. Also, thein vitrobiocompatibility and cytocompatibility of the scaffolds were tested using mesenchymal stem cells (MSCs), and cells found to be attached to the scaffold walls.

Preparation of laminated poly(ε-caprolactone)-gelatin-hydroxyapatite nanocomposite scaffold bioengineered via compound techniques for bone substitution

In this research, new bioactive nanocomposite scaffolds were successfully developed using poly(ε-caprolactone) (PCL), cross-linked gelatin and nanoparticles of hydroxyapatite (HAp) after testing different solvents and methods. First, HAp powder was synthesized via a chemical precipitation technique and characterized. Then, the nanocomposites were prepared through layer solvent casting combined with freeze-drying and lamination techniques. According to the results, the increasing of the PCL weight in the scaffolds led to the improvement of the mechanical properties. The amount of ultimate stress, stiffness and also elastic modulus increased from 8 MPa for 0% wt PCL to 23.5 MPa for 50% wt PCL. The biomineralization study revealed the formation of an apatite layer on the scaffolds after immersion in simulated body fluid (SBF). The Ca-P ratios were in accordance to nonstoichiometric biological apatite, which was approximately 1.67. The in vitro biocompatibility and cytocompatibility of the scaffolds were tested using mesenchymal stem cells (MSCs), and the results indicated no sign of toxicity, and cells were found to be attached to the scaffold walls. The in vivo biocompatibility and osteogenesis of these scaffolds in the animal experiments is also under investigation, and the result will be published at the end of the study.

Significant differences in skin irritation by common suture materials assessed by a comparative computerized objective method

BACKGROUND

Erythema can be described only through subjective evaluation, except when it is quantified by digital image analysis software. Using such software, the authors performed comparisons of the erythema produced after skin closure of clean surgical wounds. Five suture materials were compared with respect to the local skin irritation that was caused. Different quantities of erythema are produced by suture material after the skin closure of clean surgical wounds. The authors present an objective method of measuring how unreactive a suture material is in comparison with another when applied to the skin.

METHODS

The suture materials polydioxanone, polypropylene blue, polyamide 6, metallic clips, and polyglactin were compared in the present study. Digital photographs of 100 patients were compared by means of software, evaluating red color superiority (mean value of red color) in the region surrounding the wound.

RESULTS

The least to most irritation caused to the skin by different suture materials was established for paired data. The Kolmogorov-Smirnov criterion and the Wilcoxon signed rank test were used. Polydioxanone was found to have the best performance, followed in order by polyglactin, polyamide, polypropylene, and metallic clips. Immediately after suture removal, differences between the effects of suture materials were statistically significant on postoperative day 10.

CONCLUSIONS

Absorbable sutures can be used in skin closure of clean surgical wounds and can produce less erythematous reaction than nonabsorbable ones. Digital image analysis is a reliable method of quantitative evaluation of skin erythema resulting after skin closure of surgical wounds.

Mesenchymal stem cell responses to bone-mimetic electrospun matrices composed of polycaprolactone, collagen I and nanoparticulate hydroxyapatite

The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL), collagen I, and hydroxyapatite (HA) nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA). The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL), 100% collagen I (col), and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA). Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications.

Trocar-guided mesh repair of vaginal prolapse using partially absorbable mesh: 1 year outcomes

OBJECTIVE

To evaluate anatomic and functional outcomes at 1-year following trocar-guided transvaginal prolapse repair using a partially absorbable mesh.

STUDY DESIGN

Prospective multicentre cohort study at 11 international sites. One hundred twenty-seven patients with pelvic organ prolapse stage ≥ III had surgery and were evaluated at 3 months and 1-year postsurgery compared with baseline. Instruments of measurements: Pelvic Organ Prolapse Quantification, Pelvic Floor Distress Inventory-20, Pelvic Floor Impact Questionnaire-7, Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire-12, and Patients Global Impression of Change.

RESULTS

Anatomic success, defined as prolapse stage ≤ I in the treated vaginal compartments, was 77.4% (95% confidence interval, 69.0-84.4%). Significant improvements in bother, quality of life, and sexual function were detected at 3 months and 1 year compared with baseline. At 1-year after surgery, 86.2% of patients indicated their prolapse situation to be "much better." Mesh exposure rate was 10.2% and rate of de novo dyspareunia 2% at 1 year.

CONCLUSION

These results demonstrate improved anatomic support, associated with excellent functional improvements, without apparent safety concerns.