A Simple Solution for Infractured Lateral Nasal Osteotomy Lines During Revision or Primary Rhinoplasty: Osseos Stabilization With Polydioxanone Sutures.

ABSTRACT: In addition to precautions taken with perioperative surgical techniques, nasal packing and external nasal splinting are frequently employed to ensure the stability of the nasal bones following osteotomies performed during rhinoplasty. However, despite these precautions, nasal bone fragments, generally caused by trauma or healing problems, can approach the midline, progress in a posterior direction and heal with malunion in an infractured manner. Since cavities on the infractured side can result in asymmetries and/or airway narrowing, revision osteotomy is required to correct these problems. Subsequent potential recurrent infractures caused by nasal fragments can easily be prevented with late-absorbed sutures passing through the neighboring holes and opening near the osteotomy lines. This technique would be useful for both primary and secondary rhinoplasty, but especially in secondary rhinoplasty operations. (Level of Evidence: Level IV).

First-in-Human Study with Eight Patients Using an Absorbable Vena Cava Filter for the Prevention of Pulmonary Embolism.

PURPOSE: To prospectively evaluate the initial human experience with an absorbable vena cava filter designed for transient protection from pulmonary embolism (PE). MATERIALS AND METHODS: This was a prospective, single-arm, first-in-human study of 8 patients with elevated risk of venous thromboembolism (VTE). Seven absorbable IVC filters (made of polydioxanone that breaks down into H2O and CO2 in 6 mo) were placed prophylactically before orthopedic (n = 5) and gynecologic (n = 2) surgeries, and 1 was placed in a case of deep vein thrombosis. Subjects underwent CT cavography and abdominal radiography before and 5, 11, and 36 weeks after filter placement to assess filter migration, embolization, perforation, and caval thrombosis and/or stenosis. Potential PE was assessed immediately before and 5 weeks after filter placement by pulmonary CT angiography. RESULTS: No symptomatic PE was reported throughout the study or detected at the planned 5-week follow-up. No filter migration was detected based on the fixed location of the radiopaque markers (attached to the stent section of the filter) relative to the vertebral bodies. No filter embolization or caval perforation was detected, and no caval stenosis was observed. Throughout the study, no filter-related adverse events were reported. CONCLUSIONS: Implantation of an absorbable vena cava filter in a limited number of human subjects resulted in 100% clinical success. One planned deployment was aborted as a result of stenotic pelvic veins, resulting in 89% technical success. No PE or filter-related adverse events were observed.

In Vitro and in Vivo Biocompatibility and Degradability Evaluation of Modified Polydioxanone Plate.

BACKGROUND: Polydioxanone (PDS) has been widely used in the medical field over the past 30 years. In the 2000s, PDS plate began to be used for rhinoplasty and septoplasty. However, in Asia PDS plates are not widely used due to lack of awareness and high prices. The authors devised a method of producing a modified PDS (m-PDS; Rhinoblock Material & Design Co., Gyeonggi-do, Sothh Korea) at low cost, and compared the biocompatibilities and degradabilities of plates produced with m-PDS and commercial PDS plates (Ethicon, Somerville, NJ) in vivo and in vitro. METHODS: The melting point and decomposition rate of m-PDS were determined by differential scanning calorimetry and thermogravimetric analysis and its tensile strength was also measured. Implants (1 cm × 1 cm × 0.15 mm sized) were inserted subcutaneously into mice and harvested en bloc 2, 5, 10, 15, or 25 weeks later. Tissues were stained with hematoxylin and eosin or Masson's trichrome to evaluate inflammation, extracellular matrix deposition, and vascularization, and plate degradability was also assessed. RESULTS: No significant difference was observed between the thermal analysis and tensile test results of m-PDS and PDS plates. m-PDS started to degrade in vivo from around 10 weeks, and commercial PDS plates from around 15 weeks. After 25 weeks in vivo, both products were completely degraded and not observed in tissue slides. Histologic analysis of excised specimens showed m-PDS and PDS were similar in terms of inflammation, extracellular matrix deposition, and vascularization. CONCLUSION: In vivo and in vitro experiments detected no significant difference between the biocompatibilities and degradabilities of modified and commercial PDS plates. The results of this study suggest that the modified PDS can be used to produce versatile, low cost, absorbable graft materials for rhinoplasty and septoplasty.

Orbit in a Box: A Simplified Technique for Patient-Specific Virtually Planned Orbital Floor Reconstruction.

PURPOSE: Possibilities for the reconstruction of orbital floor fractures have been extensive for years with regard to materials, methods and differential indications and are inconsistent worldwide. With the spread of CAD/CAM techniques, new and mostly time-consuming possibilities for orbital floor reconstructions have been added. METHODS: The simple and time-efficient CT-to-patient-specific implant workflow presented here shows that a "form-box" can be created from a patient's computer tomography data set using planning software and a 3D printer. The box is then used to form a patient-specific implant for orbital floor reconstruction: here polydioxanone foil was used, for which stable thermoplastic deformability has been demonstrated for 3D reconstructions. RESULTS: Patient-specific thermoplastic shaping of polydioxanone is feasible in a theoretical clinical setting, though its thermoplastic shaping is not yet certified for clinical use. However, a flexible adaptation of the "form-box" design to other materials is possible by setting a single planning parameter. CONCLUSIONS: The simple structure of the box and its straightforward planning/fabrication process with widely available low-cost materials offer the possibility that a surgeon without a 3D specialist can produce a "form-box" for next day surgery if needed.

In vitro evaluation of the modified forwarder knot used to end a continuous suture pattern in large-gauge suture.

OBJECTIVE: To evaluate the strength and size of forwarder end (FE) knots modified to end continuous suture lines compared with Aberdeen (AB), square (SQ), and surgeon's (SU) knots. STUDY DESIGN: In vitro mechanical study. STUDY POPULATION: Knotted suture. METHODS: Knots were tied with 2 USP (United States Pharmacopeia) polydioxanone, 2 USP, and 3 USP polyglactin 910 and tested on a universal testing machine under linear tension. Mode of failure and knot holding capacity (KHC) were recorded, and relative knot security (RKS) was calculated. Knot volume and weight were determined by digital micrometer and balance. Knot holding capacity, RKS, size, and weight between knot type, number of throws, and suture type and size were compared by using analysis of variance testing, with P < .05 considered significant. RESULTS: In all suture types and number of throws, FE knot KHC/RKS was 28% to 66.99% (1.2-1.6 fold) stronger compared with SQ/SU knots (P < .001). For 2 USP polydioxanone, FE knots had 10% (1.1 fold) higher KHC/RKS compared with AB knots (P < .042). However, in 2 and 3 USP polyglactin 910, FE knot KHC/RKS values were not different from those of AB knots (P > .080). Forwarder end/AB knots failed by suture breakage at the knot, whereas some SQ/SU knots unraveled. Forwarder end knots in 2 and 3 USP polyglactin 910 were 21.1% to 44.4% (1.2-1.4 fold) smaller compared with SQ/SU knots (P < .028). Forwarder end knots in 2 and 3 USP polyglactin 910 were 40% to 99% (1.4-2.0 fold) larger compared with AB knots (P < .001). CONCLUSION: Forwarder end knots provided increased KHC/RKS compared with SQ/SU knots. CLINICAL RELEVANCE: Forwarder end knots should be considered for closures when suture is placed under tension.

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.

Development of a Tissue-Engineered Artificial Ligament: Reconstruction of Injured Rabbit Medial Collateral Ligament With Elastin-Collagen and Ligament Cell Composite Artificial Ligament.

Ligament reconstruction using a tissue-engineered artificial ligament (TEAL) requires regeneration of the ligament-bone junction such that fixation devices such as screws and end buttons do not have to be used. The objective of this study was to develop a TEAL consisting of elastin-coated polydioxanone (PDS) sutures covered with elastin and collagen fibers preseeded with ligament cells. In a pilot study, a ring-type PDS suture with a 2.5 mm (width) bone insertion was constructed with/without elastin coating (Ela-coat and Non-coat) and implanted into two bone tunnels, diameter 2.4 mm, in the rabbit tibia (6 cases each) to access the effect of elastin on the bond strength. PDS specimens taken together with the tibia at 6 weeks after implantation indicated growth of bone-like hard tissues around bone tunnels accompanied with narrowing of the tunnels in the Ela-coat group and not in the Non-coat group. The drawout load of the Ela-coat group was significantly higher (28.0 ± 15.1 N, n = 4) than that of the Non-coat group (7.6 ± 4.6 N, n = 5). These data can improve the mechanical bulk property of TEAL through extracellular matrix formation. To achieve this TEAL model, 4.5 × 106 ligament cells were seeded on elastin and collagen fibers (2.5 cm × 2.5 cm × 80 µm) prior to coil formation around the elastin-coated PDS core sutures having ball-shape ends with a diameter of 2.5 mm. Cell-seeded and cell-free TEALs were implanted across the femur and the tibia through bone tunnels with a diameter of 2.4 mm (6 cases each). There was no incidence of TEAL being pulled in 6 weeks. Regardless of the remarkable degradation of PDS observed in the cell-seeded group, both the elastic modulus and breaking load of the cell-seeded group (n = 3) were comparable to those of the sham-operation group (n = 8) (elastic modulus: 15.4 ± 1.3 MPa and 18.5 ± 5.7 MPa; breaking load: 73.0 ± 23.4 N and 104.8 ± 21.8 N, respectively) and higher than those of the cell-free group (n = 5) (elastic modulus: 5.7 ± 3.6 MPa; breaking load: 48.1 ± 11.3 N) accompanied with narrowed bone tunnels and cartilage matrix formation. These data suggest that elastin increased the bond strength of TEAL and bone. Furthermore, our newly developed TEAL from elastin, collagen, and ligament cells maintained the strength of the TEAL even if PDS was degraded.

Biomechanical performance of the Actifit® scaffold is significantly improved by selection of irrigation fluid.

PURPOSE: Clinical reports on meniscal scaffolds seem promising, albeit relatively paucity exists regarding their biomechanical behavior. The aim of the study is to delineate the impact of differing suture materials and the type as well as the temperature of the irrigation fluid on the pull-out strength of a polyurethane meniscal scaffold (Actifit®). MATERIALS AND METHODS: 128 specimens were utilized with horizontal sutures and uniaxial load-to-failure testing was performed. We compared two different suture materials-polydioxanone (PDS) and non-absorbable, braided polyester sutures (NABP)-as well as two common irrigation fluids-lactated Ringer's and electrolyte-free, hypotonic Mannitol-Sorbitol. All specimens were further evaluated according to two different temperatures [room temperature (20 °C) and near-core body temperature (37 °C)]. RESULTS: Mean load-to-failure was 53.3 ± 6.5 N. There was no significant difference between the NABP and the PDS group. Ringer group showed a significantly higher load-to-failure compared to Purisole (P = .0002). This was equivalent for both PDS (P = .0008) and NABP sutures (P = .0008). Significantly higher failure loads could be established for the 37° group (P = .041); yet, this difference was neither confirmed for the PDS or in in the NABP subgroup. Only the subgroup using Purisole at 37° showed significantly higher failure loads compared to 20° (P = .017). CONCLUSIONS: This study underlines the potential to improve pull-out strength during implantation of an Actifit® scaffold by alteration of the type of irrigation fluid. Lactated Ringer solution provided the highest construct stability in regard to load-to-failure testing and should be considered whenever implantation of a polyurethane meniscal scaffold is conducted.

Use of an Absorbable Urethral Stent for the Management of a Urethral Stricture in a Stallion.

OBJECTIVE: To describe the successful management of a urethral stricture with an absorbable stent in a stallion. STUDY DESIGN: Clinical report. ANIMALS: Stallion with a urethral stricture. RESULTS: A 12-year-old Thoroughbred breeding stallion was evaluated for acute onset of colic. Uroperitoneum because of presumptive urinary bladder rupture, with urethral obstruction by a urethrolith, was diagnosed. The uroperitoneum was treated conservatively. The urethrolith was removed through a perineal urethrotomy. Approximately 15 weeks after urethrolith removal, the stallion presented with a urethral stricture. The stricture was unsuccessfully treated with an indwelling urinary catheter and 4 attempts at balloon dilation. Eight weeks after diagnosis of stricture, an absorbable polydioxanone (20 mm × 80 mm) urethral stent was implanted under percutaneous, ultrasound guidance. Urethroscopy was performed at 70, 155, and 230 days after stent placement and the endoscope passed through the affected site without complication. Urethroscopy at 155 days showed the stent had been reabsorbed. Follow-up 20 months after stent placement reports the stallion was able to void a normal urine stream. CONCLUSIONS: Absorbable urethral stent placement was a feasible treatment for urethral stricture in this stallion.

Biodegradable polydioxanone stents in the treatment of adult patients with tracheal narrowing.

BACKGROUND: Biodegradable stents that disintegrate after a period of time are expected to be well tolerated and have advantages over other stents that are more commonly used in practice today. Polydioxanone is a biodegradable polymer that is widely used during surgery with absorbable sutures. METHODS: We present cases from the first four patients to undergo a tracheal polydioxanone stent insertion. Indications included significant non-malignant tracheal stenosis in cases where primary surgical treatment was not possible. The stents were implanted using rigid bronchoscopy and patients received regular follow-ups as needed. This use of biodegradable stents in adult patients was a novel, previously untested approach. The study was approved by the Institutional Ethics Committee and was based on a project entitled; "Biodegradable stents in the management of stenoses of large airways" (project NT 14146-3/2013). RESULTS: Six biodegradable stents were implanted in four patients with benign stenoses. No technical difficulties occurred and no serious or life-threatening events were recorded. All patients reported some benefit from treatment. CONCLUSION: Polydioxanone tracheal stents can be considered when a need for temporary support is expected, and as an alternative to other stents if the latter could compromise the patient. Owing to limited experience and observed disadvantages, further research is needed to fully assess this treatment. TRIAL REGISTRATION: This work is based on project NT14146 - Biodegradable stents in the management of stenoses of the large airways (2013-2015, MZ0/NT), registered from May 1, 2013 in The Research and Development and Innovation Information System of the Czech Republic and in ClinicalTrials.gov, reg. no. NCT02620319, December 2, 2015.

Dental pulp stem cell responses to novel antibiotic-containing scaffolds for regenerative endodontics.

AIM: To evaluate both the drug-release profile and the effects on human dental pulp stem cells' (hDPSC) proliferation and viability of novel bi-mix antibiotic-containing scaffolds intended for use as a drug delivery system for root canal disinfection prior to regenerative endodontics. METHODOLOGY: Polydioxanone (PDS)-based fibrous scaffolds containing both metronidazole (MET) and ciprofloxacin (CIP) at selected ratios were synthesized via electrospinning. Fibre diameter was evaluated based on scanning electron microscopy (SEM) images. Pure PDS scaffolds and a saturated CIP/MET solution (i.e. 50 mg of each antibiotic in 1 mL) (hereafter referred to as DAP) served as both negative (nontoxic) and positive (toxic) controls, respectively. High-performance liquid chromatography (HPLC) was performed to investigate the amount of drug(s) released from the scaffolds. WST-1(®) proliferation assay was used to evaluate the effect of the scaffolds on cell proliferation. LIVE/DEAD(®) assay was used to qualitatively assess cell viability. Data obtained from drug release and proliferation assays were statistically analysed at the 5% significance level. RESULTS: A burst release of CIP and MET was noted within the first 24 h, followed by a sustained maintenance of the drug(s) concentration for 14 days. A concentration-dependent trend was noticed upon hDPSCs' exposure to all CIP-containing scaffolds, where increasing the CIP concentration resulted in reduced cell proliferation (P < 0.05) and viability. In groups exposed to pure MET or pure PDS scaffolds, no changes in proliferation were observed. CONCLUSIONS: Synthesized antibiotic-containing scaffolds had significantly lower effects on hDPSCs proliferation when compared to the saturated CIP/MET solution (DAP).

Application of Computer-Aided Designing and Rapid Prototyping Technologies in Reconstruction of Blowout Fractures of the Orbital Floor.

INTRODUCTION: Traumatology of the maxillofacial region represents a wide range of different types of facial skeletal injuries and encompasses numerous treatment methods. Application of computer-aided design (CAD) in combination with rapid prototyping (RP) technologies and three-dimensional computed tomography techniques facilitates surgical therapy planning for efficient treatment. OBJECTIVE: The purpose of this study is to determine the efficiency of individually designed implants of poly-DL-lactide (PDLLA) in the reconstruction of blowout fractures of the orbital floor. METHODS: In the course of a surgical treatment, individually designed implants manufactured by CAD/RP technologies were used. Preoperative analysis and postoperative monitoring were conducted to evaluate the successfulness of orbital floor reconstruction using customized PDLLA implants, based on: presence of diplopia, paresthesia of infraorbital nerve, and presence of enophthalmos. RESULTS: In 6 of the 10 patients, diplopia completely disappeared immediately after surgical procedure. Diplopia gradually disappeared after 1 month in 3 patients, whereas in 1, it remained even after 6 months. In 7 patients, paresthesia disappeared within a month after surgery and in 3 patients within 2 months. Postoperative average Orbital volume (OV) of the injured side (13.333 ±â€Š3.177) was significantly reduced in comparison with preoperative OV (15.847 ±â€Š3.361) after reconstruction of the orbital floor with customized PDLLA implant (P < 0.001). Thus, average OV of corrected orbit was not different compared with the OV of the uninjured orbit (P = 0.981). CONCLUSIONS: Reconstruction of blowout fractures of the orbital floor by an individually designed PDLLA implant combined with virtual preoperative modeling allows easier preoperative preparation and yields satisfactory functional and esthetic outcomes.

Implantation of a novel tissue-engineered graft in a large tendon defect initiated inflammation, accelerated fibroplasia and improved remodeling of the new Achilles tendon: a comprehensive detailed study with new insights.

We constructed a new artificial collagen-based graft as a tendon proper and covered it with a polydioxanone sheath. This bioimplant was tested in vitro and also its effectiveness was tested in a large tendon defect model in vivo. A 2-cm full defect in the left Achilles tendon of all animals (n = 120) was created. The animals were andomly divided into three groups: control (n = 40), treated with collagen-based graft (n = 40) and treated with collagen-Polydioxanone-based graft (n = 40). Clinical examination was done weekly. The animals were euthanized at 60 and 120 days post-injury (DPI). The serum level of platelet-derived growth factor (PDGF) was measured. Hydroxyproline and dry matter content together with gross morphologic, histomorphometric, ultrastructural and biomechanical characteristics of the healing tissues were studied. The mechanism of host-graft interactions was studied in another 55 pilot animals. The graft was able to initiate inflammation, accelerate fibroplasia and improve remodeling of the neotenon in the defect area. Except for small remnants, most parts of the implants were gradually absorbed and substituted by a newly regenerated tendon. The preserved remnants were accepted as a part of neotenon and acted as scaffolds for the newly regenerated collagen fibrils. Unlike the controls, the treated lesions showed lower peritendinous adhesion, muscle fibrosis and atrophy and higher hydroxyproline concentration, dry matter content, ultimate strength, yield strength and modulus of elasticity. Numbers, diameter, density and differentiation of collagen fibrils were also greater in the treated lesions than the control ones. This study showed that the implant was cytocompatible, biodegradable, biocompatible and effective in tendon healing.

Polydioxanone biodegradable stent placement in a canine urethral model: analysis of inflammatory reaction and biodegradation.

PURPOSE: To investigate the inflammatory reaction and perform quantitative analysis of biodegradation after placement of a polydioxanone (PDO) biodegradable stent in a canine urethral model. MATERIALS AND METHODS: PDO biodegradable stents were placed in the proximal and distal urethra of nine male mongrel dogs. The dogs were euthanized 4 weeks (group A; n = 3), 8 weeks (group B; n = 3), or 12 weeks (group C; n = 3) after stent placement. The luminal diameter of the stent-implanted urethra was assessed by follow-up retrograde urethrography, and histologic findings were obtained after the dogs were killed. Stents were removed after euthanasia, and their surface morphology and molecular weight were evaluated. Hematologic examination was performed to evaluate inflammatory reaction. RESULTS: Stent placement was technically successful in all dogs. The average luminal diameter gradually decreased. The average number of epithelial layers (2.93 vs 4.42; P < .001), the average thickness of papillary projection (0.80 mm vs 1.28 mm; P < .001), and the average thickness of submucosal fibrosis (0.34 mm vs 0.49 mm ; P < .001) were significantly increased in group B versus group A. There were no significant differences between group B and group C. The average inflammatory cell infiltration did not differ significantly in the three groups. Molecular weight losses were 54% in group A and 84% in group B. In group C, PDO stents were completely decomposed. CONCLUSIONS: An experimental study in a canine urethral model has demonstrated acceptable inflammatory reaction with gradually increasing granulation tissue but no luminal obstruction within 12 weeks.

Electrospun polydioxanone/fucoidan blend nanofibers loaded with anti-cancer precipitate from Jaspis diastra and paclitaxel: Physico-chemical characterization and in-vitro screening.

Nanofibers for drug delivery systems have gained much attention during the past years. This paper describes for the first time the loading of a bioactive precipitate (JAD) from the marine sponge Jaspis diastra in PDX and fucoidan-PDX. JAD was characterized by LC-MS/MS and the major component was jaspamide (1) with a purity of 62.66 %. The cytotoxicity of JAD was compared with paclitaxel (PTX). JAD and PTX displayed IC50 values of 1.10 ± 0.7 µg/mL and 0.21 ± 0.12 µg/mL on skin fibroblasts L929 cells whilst their IC50 values on uveal MP41 cancer cells, were 2.10 ± 0.55 µg/mL and 1.38 ± 0.68 µg/mL, respectively. JAD was found to be less cytotoxic to healthy fibroblasts compared to PTX. JAD and PTX loaded scaffolds showed sustained release over 96 h in physiological medium which is likely to reduce the secondary cytotoxic effect induced by JAD and PTX alone. The physico-chemical properties of the loaded and unloaded scaffolds together with their degradation and action on tumor microenvironment by using L929 and MP41 cells were investigated. JAD and PTX at a concentration of 0.5 % (drug/polymer, w/w) in the electrospun mats prevented growth and proliferation of L929 and MP41 cells. Co-culture of L929 and MP41 showed that the JAD and PTX loaded mats inhibited the growth of both cells and caused cell death.

Transduction and Genome Editing of the Heart with Adeno-Associated Viral Vectors Loaded onto Electrospun Polydioxanone Nonwoven Fabrics.

In this study, we introduce electrospun polydioxanone (PDO) nonwoven fabrics as a platform for the delivery of adeno-associated virus (AAV) vectors for transduction and genome editing by adhering them to organ surfaces, including the heart. AAV vectors were loaded onto the PDO fabrics by soaking the fabrics in a solution containing AAV vectors. In vitro, the amount of AAV vectors loaded onto the fabrics could be adjusted by changing their concentration in the solution, and the number of cells expressing the green fluorescent protein (GFP) encoded by the AAV vectors increased in correlation with the increasing amount of loaded AAV vectors. In vivo, both transduction and genome editing resulted in the observation of GFP expression around AAV vector-loaded PDO fabrics attached to the surfaces of mouse hearts, indicating effective transduction and expression at the target site. These results demonstrate the great potential of electrospun PDO nonwoven fabrics carrying therapeutic AAV vectors for gene therapy.

Electrospun nanofibrous scaffolds as a platform to reduce melanoma tumour growth, recurrence, and promote post-resection wound repair.

Wound healing following skin tumour surgery still remains a major challenge. To address this issue, polysaccharide-loaded nanofibrous mats have been engineered as skin patches on the wound site to improve wound healing while simultaneously eliminating residual cancer cells which may cause cancer relapse. The marine derived polysaccharides kappa-carrageenan (KCG) and fucoidan (FUC) were blended with polydioxanone (PDX) nanofibers due to their inherent anti-cancer activity conferred by the sulphate groups as well as their immunomodulatory properties which can reduce inflammation resulting in accelerated wound healing. KCG and FUC were released sustainably from the blend nanofibers via the Korsmeyer-Peppas kinetics. MTT assays, live/dead staining and SEM images demonstrated the toxicity of KCG and FUC towards skin cancer MP 41 cells. In addition, MP 41 cells showed reduced metastatic potential when grown on KCG or FUC containing mats. Both KCG and FUC were non- cytotoxic to healthy L 929 fibroblast cells. In vivo studies on healthy Wistar rats confirmed the non-toxicity of the nanofibrous patches as well as their improved and scarless wound healing potential. In vivo studies on tumour xenograft model further showed a reduction of 7.15 % in tumour volume in only 4 days following application of the transdermal patch.

Biodegradable stents for caustic esophageal strictures: a new therapeutic approach.

The treatment of caustic esophageal strictures is a challenging topic. Although traditional therapies have limited efficacy, most of these patients eventually require surgery. Biodegradable (BD) stents are newly designed stents for benign conditions. This is a retrospective case series of seven patients with caustic esophageal stricture. BD esophageal stents were inserted for palliation of dysphagia. The position of the stent was checked at 1, 4, 8, 12 16, 20, and 24 weeks and at the end of follow-up period. The follow-up period was 60 ± 23 (36-102) weeks. Complete dissolution of the stent occurred at 16 ± 4 (12-20) weeks. Three patients had partial/complete relief of dysphagia. The remaining four patients experienced tissue hyperplasia at the edges of the stent and required serial dilations. At the end of follow-up, all patients had partial or complete relief of dysphagia. Although BD stents have some efficiency, tissue hyperplasia is the main limiting factor. Further randomized trials are needed to determine efficiency of BD stents for caustic damage.

Lateral crural suspension flap: a novel technique to modify and stabilize the nasolabial angle.

The proper nasolabial angle is a determinant factor in achieving a pleasant result in esthetic rhinoplasty surgery. Nasal tip position depends on various interrelated elements. Its rotation should be analyzed by assessing the nasolabial angle. An increase in this angle results in an upward tilt of the base of the nose with a concomitant decrease in nasal length. Several methods have been advocated to improve this angle; unfortunately, these techniques have considerable limitations in modifying and stabilizing nasal tip rotation. The general principles for rotating the nasal tip include removing the factors that resist the rotation of the lower lateral cartilages, creating space to accommodate them, rotating the lower lateral cartilages into the desired position, and stabilizing the cartilages in the desired position. Resection of the cephalic margin of the lateral crura fulfills these goals. This report describes a straightforward and stable method that uses cephalic portions of the lower lateral crural cartilages as 2 flaps to suspend the nasal tip to the septum to modify and stabilize the nasolabial angle.

[Treatment of a postoperative rectal stenosis with a self-expanding biodegradable polydioxanone stent]. / Behandlung einer postoperativen Rektumstenose mittels eines selbstexpandierenden resorbierbaren Polydioxanon-Stents.

Rectal stricture is a serious although infrequent complication of transanal endoscopic microsurgery (TEM). In some cases, these strictures may be refractory to treatment by endoscopic balloon dilatation. Biodegradable stents might improve the outcome by providing an extended period of dilatation. Moreover, these stents can remain in place without the need to remove them. In the presented case, a biodegradable polidioxanone stent originally developed to treat benign oesophageal stenoses was used to treat a patient suffering from rectal stricture following a TEM.