Polycaprolactone Mesh Research Articles

Repair of critical-size porcine craniofacial bone defects using a collagen–polycaprolactone composite biomaterial

Regenerative medicine approaches for massive craniomaxillofacial (CMF) bone defects face challenges associated with the scale of missing bone, the need for rapid graft-defect integration, and challenges related to inflammation and infection. Mineralized collagen scaffolds have been shown to promote mesenchymal stem cell osteogenesis due to their porous nature and material properties, but are mechanically weak, limiting surgical practicality. Previously, these scaffolds were combined with 3D-printed polycaprolactone (PCL) mesh to form a scaffold-mesh composite to increase strength and promote bone formation in sub-critical sized porcine ramus defects. Here, we compare the performance of mineralized collagen–PCL composites to the PCL mesh in a critical-sized porcine ramus defect model. While there were no differences in overall healing response between groups, our data demonstrated broadly variable metrics of healing regarding new bone infiltration and fibrous tissue formation. Abscesses were present surrounding some implants and PCL polymer was still present after 9–10 months of implantation. Overall, while there was limited successful healing, with 2 of 22 implants showed substantial levels of bone regeneration, and others demonstrating some form of new bone formation, the results suggest targeted improvements to improve repair of large animal models to more accurately represent CMF bone healing. Notably, strategies to increase osteogenesis throughout the implant, modulate the immune system to support repair, and employ shape-fitting tactics to avoid implant micromotion and resultant fibrosis. Improvements to the mineralized collagen scaffolds involve changes in pore size and shape to increase cell migration and osteogenesis and inclusion or delivery of factors to aid vascular ingrowth and bone regeneration.

Erratum: Polycaprolactone Mesh for Asian Rhinoplasty: Outcomes and Complications of Composite Septal Extension Graft Compared to Mesh-Only Graft.

Erratum: Polycaprolactone Mesh for Asian Rhinoplasty: Outcomes and Complications of Composite Septal Extension Graft Compared to Mesh-Only Graft.

Fabrication of Drug-Eluting Polycaprolactone/poly(lactic-co-glycolic Acid) Prolapse Mats Using Solution-Extrusion 3D Printing and Coaxial Electrospinning Techniques.

We developed biodegradable drug-eluting prolapse mats using solution-extrusion 3D printing and coaxial electrospinning techniques. The mats were composed of polycaprolactone (PCL) mesh and lidocaine-, estradiol-, metronidazole-, and connective tissue growth factor (CTGF)-incorporated poly(lactic-co-glycolic acid) (PLGA) nanofibers that mimic the structure of the natural extracellular matrix of most connective tissues. The mechanical properties of degradable prolapse membrane were assessed and compared to commercial non-degradable polypropylene knitted meshes clinically used for pelvic organ prolapse (POP) repair. The release behaviors of the drug-loaded hybrid degradable membranes were also characterized. The experimental results suggest that 3D-printed PCL meshes exhibited comparable strengths to commercial POP meshes and survived through 10,000 cycles of fatigue test without breakage. Hybrid PCL meshes/PLGA nanofibrous membranes provided a sustainable release of metronidazole, lidocaine, and estradiol for 4, 25, and 30 days, respectively, in vitro. The membranes further liberated high levels of CTGF for more than 30 days. The animal tests show that the mechanical property of PCL mesh decreased with time, mainly due to degradation of the polymers post-implantation. No adverse effect of the mesh/nanofibers was noted in the histological images. By adopting solution-extrusion 3D printing and coaxial electrospinning, degradable drug-eluting membranes can be fabricated for POP applications.

Polycaprolactone Mesh for Asian Rhinoplasty: Outcomes and Complications of Composite Septal Extension Graft Compared to Mesh-Only Graft.

Despite the great demand of aesthetic rhinoplasty in Asian population, it is difficult to obtain the lasting ideal tip projection along with lengthening of the nose due to the small and weak nasal septum. The shortage of available septal cartilage to work with is another major obstacle. A retrospective study was conducted between January 2017 and December 2019 in Seoul, Korea. A total of 774 patients underwent septorhinoplasty using polycaprolactone (PCL) mesh for the cosmetic enhancement of the nasal tip and the projection. Comparisons of aesthetic outcomes, patients' satisfaction surveys, and complications were performed between PCL mesh-only group and composite PCL group. Of all the patients, 97.5% of the patients in composite PCL group were rated more than 3 scores in aesthetic outcomes, whereas 90.4% in mesh-only group (p-value = 0.0002). About 96.7% of the patients with composite PCL rated their satisfaction level as more than satisfied, whereas 94.3% in mesh-only group (p-value = 0.0365). Overall, there were 17 patients in composite PCL group who exhibited complications including decreased tip projection, deviated nasal tip, mesh infection, and mesh exposure. However, there were two patients who had mesh injection in mesh-only group. Septorhinoplasty with septal extension graft using composite PCL graft provides robust support to the aesthetically modified projection and the lengthened nose without obvious complications on the nasal tip. Such technique allows surgeons to overcome the nature of Asian nose that is weak and small, and also provides satisfaction to patients who desire ideal tip projections and dramatic changes.

Development and Evaluation of a Human Skin Equivalent in a Semiautomatic Microfluidic Diffusion Chamber.

There is an increasing demand for transdermal transport measurements to optimize topical drug formulations and to achieve proper penetration profile of cosmetic ingredients. Reflecting ethical concerns the use of both human and animal tissues is becoming more restricted. Therefore, the focus of dermal research is shifting towards in vitro assays. In the current proof-of-concept study a three-layer skin equivalent using human HaCaT keratinocytes, an electrospun polycaprolactone mesh and a collagen-I gel was compared to human excised skin samples. We measured the permeability of the samples for 2% caffeine cream using a miniaturized dynamic diffusion cell (“skin-on-a-chip” microfluidic device). Caffeine delivery exhibits similar transport kinetics through the artificial skin and the human tissue: after a rapid rise, a long-lasting high concentration steady state develops. This is markedly distinct from the kinetics measured when using cell-free constructs, where a shorter release was observable. These results imply that both the established skin equivalent and the microfluidic diffusion chamber can serve as a suitable base for further development of more complex tissue substitutes.

Biodegradable implants for orbital wall fracture reconstruction.

BackgroundDue to the different handling properties of unsintered hydroxyapatite particles/poly-L-lactic acid (uHA/PLLA) and polycaprolactone (PCL), we compared the surgical outcomes and the postoperative implantation accuracy between uHA/PLLA and PCL meshes in orbital fracture repair.MethodsPatients undergoing orbital wall reconstruction with PCL and uHA/PLLA mesh, between 2017 and 2019, were investigated retrospectively. The anatomical accuracy of the implant in bony defect replacement and the functional outcomes such as diplopia, ocular motility, and enophthalmos were evaluated.ResultsNo restriction of eye movement was reported in any patient (n=30 for each group), 6 months postoperatively. In the PCL group, no patient showed diplopia or enophthalmos, while the uHA/PLLA group showed two patients with diplopia and one with enophthalmos. Excellent anatomical accuracy of implants was observed in 27 and 22 patients of the PCL and uHA/PLLA groups, respectively. However, this study showed that there were neither any significant differences in the surgical outcomes like diplopia and enophthalmos nor any complications with the two well-known implants.ConclusionPCL implants and uHA/PLLA implants are safe and have similar levels of complications and surgical outcomes in orbital wall reconstruction.

Combining multi-scale 3D printing technologies to engineer reinforced hydrogel-ceramic interfaces

Multi-material 3D printing technologies that resolve features at different lengths down to the microscale open new avenues for regenerative medicine, particularly in the engineering of tissue interfaces. Herein, extrusion printing of a bone-biomimetic ceramic ink and melt electrowriting (MEW) of spatially organized polymeric microfibres are integrated for the biofabrication of an osteochondral plug, with a mechanically reinforced bone-to-cartilage interface. A printable physiological temperature-setting bioceramic, based on α-tricalcium phosphate, nanohydroxyapatite and a custom-synthesized biodegradable and crosslinkable poloxamer, was developed as bone support. The mild setting reaction of the bone ink enabled us to print directly within melt electrowritten polycaprolactone meshes, preserving their micro-architecture. Ceramic-integrated MEW meshes protruded into the cartilage region of the composite plug, and were embedded with mechanically soft gelatin-based hydrogels, laden with articular cartilage chondroprogenitor cells. Such interlocking design enhanced the hydrogel-to-ceramic adhesion strength >6.5-fold, compared with non-interlocking fibre architectures, enabling structural stability during handling and surgical implantation in osteochondral defects ex vivo. Furthermore, the MEW meshes endowed the chondral compartment with compressive properties approaching those of native cartilage (20-fold reinforcement versus pristine hydrogel). The osteal and chondral compartment supported osteogenesis and cartilage matrix deposition in vitro, and the neo-synthesized cartilage matrix further contributed to the mechanical reinforcement at the ceramic-hydrogel interface. This multi-material, multi-scale 3D printing approach provides a promising strategy for engineering advanced composite constructs for the regeneration of musculoskeletal and connective tissue interfaces.

Characterizing the invasion of different breast cancer cell lines with distinct E-cadherin status in 3D using a microfluidic system

E-cadherin is a cell-cell adhesion protein that plays a prominent role in cancer invasion. Inactivation of E-cadherin in breast cancer can arise from gene promoter hypermethylation or genetic mutation. Depending on their E-cadherin status, breast cancer cells adopt different morphologies with distinct invasion modes. The tumor microenvironment (TME) can also affect the cell morphology and invasion mode. In this paper, we used a previously developed microfluidic system to quantify the three-dimensional invasion of breast cancer cells with different E-cadherin status, namely MCF-7, CAMA-1 and MDA-MB-231 with wild type, mutated and promoter hypermethylated E-cadherin, respectively. The cells migrated into a stable and reproducible microfibrous polycaprolactone mesh in the chip under a programmed stable chemotactic gradient. We observed that the MDA-MB-231 cells invaded the most, as single cells. MCF-7 cells collectively invaded into the matrix more than CAMA-1 cells, maintaining their E-cadherin expression. The CAMA-1 cells exhibited multicellular multifocal infiltration into the matrix. These results are consistent with what is seen in vivo in the cancer biology literature. In addition, comparison between complete serum and serum gradient conditions showed that the MDA-MB-231 cells invaded more under the serum gradient after one day, however this behavior was inverted after 3 days. The results showcase that the microfluidic system can be used to quantitatively assess the invasion behavior of cancer cells with different E-cadherin expression, for a longer period than conventional invasion models. In the future, it can be used to quantitatively investigate effects of matrix structure and cell treatments on cancer invasion.

Fabrication of a Large-Area, Fused Polymer Micromold Based on Electric-Field-Driven (EFD) μ-3D Printing.

An electric-field-driven (EFD), μ-3D printed, fused polymer technique has been developed for the fabrication of large-area microscale prototype molds using typical polymer materials, including microcrystalline wax (MC-wax), polycaprolactone (PCL), and polymathic methacrylate (PMMA). This work proposes an alternative for large area microscale modes and overcomes the limitation of high cost in the traditional mold manufacturing industry. The EFD principle enables printing of fused polymers materials more than one order of magnitude lower than the nozzle diameter, contributing to the necking effect of the Taylor cone jet, which is the key factor to achieve the microscale manufacturing. Numerical simulation of electric field distribution between the meniscus and substrate was carried out to elucidate the dependence of electric field distribution on the meniscus condition of three types of polymers under printable voltage, and the electrical field parameters for the EFD μ-3D printing were determined. A number of experiments were printed successfully using a large range of viscosity materials, ranging from tens of mPa·s to hundreds of thousands of mPa·s of PCL and PMMA. The differences in parameters of different materials, such as viscosity, tensile properties, and surface energy, were studied to assess their use in different fields. Using proper process parameters and a nozzle with an inner diameter of 200 μm, three different application cases were completed, including a Wax microarray and microchannel with a minimum dot diameter of 20 μm, a PCL mesh structure with a minimum line width of 5 μm, and a PMMA large-area mold with a maximum aspect ratio of 0.8. Results show that the EFD μ-3D printing has the outstanding advantages of high printing resolution and polymer material universality.

Development and characterization of a suturable biomimetic patch for cardiac applications.

3D scaffolds used to repair damaged tissues should be able to mimic both composition and functions of natural extracellular matrix, which is mainly composed of polysaccharides and proteins. In our previous research new biomimetic sponges, based on blends of alginate with gelatin, were produced and characterized for myocardial tissue engineering applications. It was observed that these scaffolds can potentially function as a promising cardiac extracellular matrix substitute, but a reinforcement is required to improve their suturing properties. Aim of the present work was the development of a suturable biomimetic patch by the inclusion of a synthetic mesh within an alginate/gelatin scaffold. The mesh, produced by dry spinning, was made of eight superimposed layers of polycaprolactone microfibers, each one rotated of 45° with respect to the adjacent one. Reinforced scaffolds were obtained through the use of a mold, specially designed to place the fibrous mesh exactly in the center of the sponge. Both the reinforcement mesh and the reinforced scaffold were characterized. A perfect integration between the mesh and the sponge was observed. The fibrous mesh reduced the capacity of the sponge to absorb water, but the degree of hydrophilicity of the material was still comparable with that of natural cardiac tissue. The reinforced system showed a suitable stability in aqueous environment and it resulted much more resistant to suturing than not reinforced scaffold and even than human arteries. Polycaprolactone mesh was not cytotoxic and the reinforced scaffold was able to support cardiomyocytes adhesion and proliferation. Overall, the obtained results confirmed that the choice to modify the alginate/gelatin sponges through the insertion of an appropriate reinforcement system turned out to be correct in view of their potential use in myocardial tissue engineering.

Proof of concept, design, and manufacture via 3‐D printing of a mesh with bactericidal capacity: Behaviour in vitro and in vivo

Currently, hernia treatment involves implantation of a mesh prosthesis, usually made of polypropylene, and the primary complication is infection of the device, which leads to an exponential increase in morbidity. Three-dimensional printing offers a method of dealing with complications of this magnitude. Therefore, in this study, the bactericidal properties and effectiveness of three-dimensional-printed meshes with polycaprolactone (PCL) and gentamicin were evaluated in vitro in Escherichia coli cultures, and their histological behaviour was examined in vivo. Different PCL meshes were implanted into four groups of rats, with 10 rats in each group: PCL meshes, PCL meshes with alginate and calcium chloride, PCL meshes with gentamicin, and PCL meshes with alginate and gentamicin. Thirty-six microporous meshes were manufactured, and their bactericidal properties were assessed. When the meshes did not include an antibiotic, an inhibition halo was not observed; when the gentamicin was free, an asymmetric inhibition area of 5.65 ± 0.46 cm2 was present; when the gentamicin was encapsulated, a rectangular area of 5.40 ± 0.38 cm2 was observed. In the rats, macroporous and microporous mesh implants produced mild inflammation and substantial fibrosis with collagen and neovascular foci. A significant difference was observed in fibroblastic activity between the PCL with alginate group and the PCL with alginate and gentamicin group microporous meshes (p = .013) and in collagen deposits between the macroporous and microporous meshes in the PCL mesh group (p = .033). The feasibility of manufacturing drug-doped printed PCL meshes containing alginate and gentamicin was verified, and the meshes exhibited bactericidal effects and good histopathological behaviour.

Titanium Nanorods Loaded PCL Meshes with Enhanced Blood Vessel Formation and Cell Migration for Wound Dressing Applications.

Proper management of nonhealing wounds is an imperative clinical challenge. For the effective healing of chronic wounds, suitable wound coverage materials with the capability to accelerate cell migration, cell proliferation, angiogenesis, and wound healing are required to protect the healing wound bed. Biodegradable polymeric meshes are utilized as effective wound coverage materials to protect the wounds from the external environment and prevent infections. Among them, electrospun biopolymeric meshes have got much attention due to their extracellular matrix mimicking morphology, ability to support cell adhesion, and cell proliferation. Herein, electrospun nanocomposite meshes based on polycaprolactone (PCL) and titanium dioxide nanorods (TNR) are developed. TNR incorporated PCL meshes are fabricated by electrospinning technique and characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy (FTIR) analysis, and X-Ray diffraction (XRD) analysis. In vitro cell culture studies, in ovo angiogenesis assay, in vivo implantation study, and in vivo wound healing study are performed. Interestingly, obtained in vitro and in vivo results demonstrated that the presence of TNR in the PCL meshes greatly improved the cell migration, proliferation, angiogenesis, and wound healing. Owing to the above superior properties, they can be used as excellent biomaterials in wound healing and tissue regeneration applications.

Curcumin release from blended polycaprolactone/polylactic acid electrospun nanofibrous meshes

There is a great interest in developing drug delivery systems that are biocompatible and release the drug in a controlled way. In this study, the release of curcumin from electrospun meshes made from polycaprolactone, polylactic acid, or their blends was studied and compared. The polymers and curcumin were dissolved in a mixture of chloroform and dimethylformamide. The beadless electrospun meshes were obtained under the following conditions: the applied voltage of 22 kV, the tip to collector distance of 13 cm, and the polymer feed rate of 0.2 ml/h. The viscosity of the polymer solution increased by increasing the percentage of polylactic acid in the mixture. As a result, the average fiber diameter of the meshes was increased. The fabricated polycaprolactone mesh showed the minimum average fiber diameter (∼120 nm) and the maximum porosity (∼71%). The hybrid nanofibrous meshes were also fabricated using two counter nozzles on both sides of the collector. The tensile strengths of the polylactic acid and polycaprolactone electrospun meshes loaded with curcumin were 19.86 and 12.64 MPa, respectively. The tensile strain of the meshes increased from 43 to 116% by increasing the polycaprolactone weight percentage in the mixture. The results showed that the physical–mechanical properties of the fabricated electrospun meshes could be tuned by polymer blending. The release of curcumin from these electrospun meshes was monitored in a buffer solution using an UV-Vis spectrophotometer. The critical parameters on the release of curcumin were found to be the type of polymers, the average diameter of nanofibers, porosity, and hydrophilicity of the meshes.

Suturable regenerated silk fibroin scaffold reinforced with 3D-printed polycaprolactone mesh: biomechanical performance and subcutaneous implantation.

The menisci have crucial roles in the knee, chondroprotection being the primary. Meniscus repair or substitution is favored in the clinical management of the meniscus lesions with given indications. The outstanding challenges with the meniscal scaffolds include the required biomechanical behavior and features. Suturability is one of the prerequisites for both implantation and implant survival. Therefore, we proposed herein a novel highly interconnected suturable porous scaffolds from regenerated silk fibroin that is reinforced with 3D-printed polycaprolactone (PCL) mesh in the middle, on the transverse plane to enhance the suture-holding capacity. Results showed that the reinforcement of the silk fibroin scaffolds with the PCL mesh increased the suture retention strength up to 400%, with a decrease in the mean porosity and an increase in crystallinity from 51.9 to 55.6%. The wet compression modulus values were significantly different for silk fibroin, and silk fibroin + PCL mesh by being 0.16 ± 0.02, and 0.40 ± 0.06 MPa, respectively. Both scaffolds had excellent interconnectivity (>99%), and a high water uptake feature (>500%). The tissue's infiltration and formation of new blood vessels were assessed by means of performing an in vivo subcutaneous implantation of the silk fibroin + PCL mesh scaffolds that were seeded with primary human meniscocytes or stem cells. Regarding suturability and in vivo biocompatibility, the findings of this study indicate that the silk fibroin + PCL mesh scaffolds are suitable for further studies to be carried out for meniscus tissue engineering applications such as the studies involving orthotopic meniscal models and fabrication of patient-specific implants.

Unique animal friendly 3D culturing of human cancer and normal cells

Two-dimensional cell culturing has proven inadequate as a reliable preclinical tumour model due to many inherent limitations. Hence, novel three-dimensional (3D) cell culture models are needed, which in many aspects can mimic a native tumour with 3D extracellular matrix. Here, we present a 3D electrospun polycaprolactone (PCL) mesh mimicking the collagen network of tissue. The naturally hydrophobic PCL mesh was subjected to O2 plasma treatment to obtain hydrophilic fibres. Biocompatibility tests performed using L929 fibroblasts show that the 3D PCL fibre unit compartments were non-toxic. The human breast cancer cell lines MCF-7 and JIMT-1, the normal-like human breast cell line MCF-10A, and human adult fibroblast were cultured in PCL meshes and cell proliferation was monitored using the AlamarBlue® assay. Confocal microscopy and cryosectioning show that the cells penetrated deep into the fibre mesh within 1 week of cell culturing. The cancer cells form spheroids with the cells attaching mainly to each other and partly to the fibres. The human adult fibroblasts stretch out along the fibres while the MCF-10A cells stretch between fibres. Overall, we show that normal and cancer cells thrive in the 3D meshes cultured in fetal bovine free medium which eliminates the use of collagen as an extracellular matrix support.

Electrospun nanofiber mesh with fibroblast growth factor and stem cells for pelvic floor repair.

Surgical outcome following pelvic organ prolapse (POP) repair needs improvement. We suggest a new approach based on a tissue-engineering strategy. In vivo, the regenerative potential of an electrospun biodegradable polycaprolactone (PCL) mesh was studied. Six different biodegradable PCL meshes were evaluated in a full-thickness abdominal wall defect model in 84 rats. The rats were assigned into three groups: (1) hollow fiber PCL meshes delivering two dosages of basic fibroblast growth factor (bFGF), (2) solid fiber PCL meshes with and without bFGF, and (3) solid fiber PCL meshes delivering connective tissue growth factor (CTGF) and rat mesenchymal stem cells (rMSC). After 8 and 24 weeks, we performed a histological evaluation, quantitative analysis of protein content, and the gene expression of collagen-I and collagen-III, and an assessment of the biomechanical properties of the explanted meshes. Multiple complications were observed except from the solid PCL-CTGF mesh delivering rMSC. Hollow PCL meshes were completely degraded after 24 weeks resulting in herniation of the mesh area, whereas the solid fiber meshes were intact and provided biomechanical reinforcement to the weakened abdominal wall. The solid PCL-CTGF mesh delivering rMSC demonstrated improved biomechanical properties after 8 and 24 weeks compared to muscle fascia. These meshes enhanced biomechanical and biochemical properties, demonstrating a great potential of combining tissue engineering with stem cells as a new therapeutic strategy for POP repair. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:48-55, 2020.

Application of the three-dimensionally printed biodegradable polycaprolactone (PCL) mesh in repair of orbital wall fractures

PurposeThe present study aims to investigate the surface characteristics and biomechanical properties of 3D-printed polycaprolactone (PCL) mesh and present the clinical outcomes of this implant in the treatment of orbital wall fractures. Patients and methodA retrospective review of patients who underwent surgery for medial, inferior and inferomedial orbital wall fractures using PCL mesh was performed between April 2017 and June 2018. Two clinical outcomes were investigated: functional recovery and anatomical accuracy of reduction detected in image. Furthermore, scanning electron microscopy was used to evaluate the microscopic morphology, surface characteristics, and porosity of the PCL mesh. ResultsAmong a total of 22 patients with a mean age of 41.3 years, the most common cause of injury was assault (54.5%). Fourteen patients (63.6%) had isolated orbital floor fractures. At postoperative 1-week follow-up, three patients (13.6%) exhibited diplopia and a further three patients (13.6%) showed restriction in ocular motility, but these patients had completely recovered by their 6-month postoperative follow-up. Ideal repair of orbital fracture was almost achieved in 21 patients (95.4%) and there were no cases of implant infection, inflammatory response, migration of implant, or hemorrhage. Microscopic imaging of PCL mesh surface revealed fully interconnected micropores with 50% porosity. ConclusionsThe repair of orbital wall fracture using PCL mesh offers reliable stabilization of orbital wall defects with a low complication rate, leading to outstanding functional and aesthetic outcomes. Therefore, PCL mesh is a good alternative for bioresorbable implants in the treatment of orbital wall fractures.

3D printing of surgical hernia meshes impregnated with contrast agents: in vitro proof of concept with imaging characteristics on computed tomography

BackgroundSelected medical implants and other 3D printed constructs could potentially benefit from the ability to incorporate contrast agents into their structure. The purpose of the present study is to create 3D printed surgical meshes impregnated with iodinated, gadolinium, and barium contrast agents and characterize their computed tomography (CT) imaging characteristics. Commercial fused deposition layering 3D printing was used to construct surgical meshes impregnated with imaging contrast agents in an in vitro model. Polycaprolactone (PCL) meshes were printed containing iodinated, gadolinium, or barium contrast; control PCL meshes without contrast were also fabricated. The three different contrast agents were mixed with PCL powder and directly loaded into the 3D printer. CT images of the three contrast-containing meshes and the control meshes were acquired and analyzed using small elliptical regions of interest to record the Hounsfield units (HU) of each mesh. Subsequently, to test their solubility and sustainability, the contrast-containing meshes were placed in a 37 °C agar solution for 7 days and imaged by CT at days 1, 3 and 7.ResultsAll 3D printed meshes were visible on CT. Iodinated contrast meshes had the highest attenuation (2528 mean HU), significantly higher than both and gadolinium (1178 mean HU) and barium (592 mean HU) containing meshes. Only barium meshes sustained their visibility in the agar solution; the iodine and gadolinium meshes were poorly perceptible and had significantly lower mean HU compared to their pre-agar solution imaging, with iodine and gadolinium present in the adjacent agar at day 7 CT.Conclusion3D prints embedded with contrast materials through this method displayed excellent visibility on CT; however, only barium mesh maintained visibility after 7 days incubation on agar at human body temperature. This method of 3D printing with barium may have potential applications in a variety of highly personalized and CT visible medical devices.

Clinical Application of Three-Dimensionally Printed Biomaterial Polycaprolactone (PCL) in Augmentation Rhinoplasty.

This clinical study aimed to investigate the safety and surgical outcome of three-dimensionally (3D) fabricated polycaprolactone (PCL) mesh in rhinoplasty. In particular, this study explored how a 3D-printed PCL mesh performs as a bioabsorbable scaffold after a long period following implantation. A retrospective review of 101 patients who received primary or secondary rhinoplasty with a PCL mesh was performed. Patient demographics and surgery-related outcomes were examined. Clinical efficacy and safety were evaluated using the Global Aesthetic Improvement Scale at postoperative 18months. From two revisional cases, a biopsy specimen of implanted PCL was acquired and histopathological analysis was performed. Of all the patients, 98.0% showed no postoperative infection-related foreign body reaction or distinct abnormal reaction, and the implants were observed to maintain long-term efficacy until 18-month follow-up. In patients who received spreader grafts, significant differences between preoperative and postoperative Cottle sign scores were found. Histopathological analysis showed features of adjacent tissue infiltration into pores of the PCL mesh and regeneration of neo-cartilaginous tissue and collagen around the mesh 20months after implantation. This study demonstrates that a novel biodegradable PCL mesh with a 3D structure is a safe and effective material for corrective rhinoplasty because it is easy to use and capable of maintaining its volume in the long term without foreign body response. This biocompatible material will have a wide range of applications as the most suitable alternative to nonabsorbable materials in rhinoplasty and reconstruction surgeries, such as fashioning spreader grafts and septal extension grafts. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Clinical Application of 3-Dimensional Printing Technology for Patients With Nasal Septal Deformities

Studies have shown the controllability and porosity of polycaprolactone as well as the use of 3-dimensional (3-D) printing for nasal reconstruction in animal models. The utility of polycaprolactone with 3-D technology in nasal cartilaginous framework reconstruction in humans remains unknown. To investigate the safety and efficacy of 3-D printed, bioresorbable polycaprolactone nasal implants. This multicenter clinical trial comprised 20 patients with caudal septal deviations who underwent septoplasty, which used a 3-D printed polycaprolactone mesh, at 2 centers in South Korea. Patients were included if they were aged 18 to 74 years and had nasal septal deviations, Nasal Obstruction Symptom Evaluation scores greater than 20, and persistent nasal obstructions. Twenty-two patients met the inclusion criteria, but 2 patients were excluded before the operation. The study was conducted from July 1, 2016, to June 30, 2017. The change in total Nasal Obstruction Symptom Evaluation score between the preoperative examination and the week 12 postoperative examination was the primary outcome. Changes in bilateral nasal cavity minimum cross-sectional area and volume on acoustic rhinometry at weeks 4 and 12 after the operation as well as changes in the nasal cavity cross-sectional area at the osteomeatal unit and nasal septum angle in the paranasal sinus on computed tomography after week 12 were among the secondary outcomes. Of the 20 patients included in the study, 4 (20%) were female, 16 (80%) were male, with a mean (SD) age of 34.95 (11.96) years. The preoperative and week 12 postoperative results revealed significant changes in the minimal cross-sectional areas on acoustic rhinometry (0.41 [SD, 0.39] vs -0.11 [SD, 0.18]; difference, 0.42; 95% CI, 0.23-0.61), nasal septum angles on computed tomography (11.22 [SD, 6.57] vs 2.89 [SD, 3.12]; difference, 8.33; 95% CI, 5.08-11.58), and Nasal Obstruction Symptom Evaluation scores (73.50 [SD, 19.88] vs 3.75 [SD, 6.26]; difference, 69.75; 95% CI, 59.22-80.28). The surgeons' convenience level with the procedure was favorable (visual analog scale score [SD], 90.90 [9.45]), and so were the patients' symptom improvements and satisfaction after 12 weeks (visual analog scale score [SD], 88.30 [9.87]). The 3-D printed, homogeneous, composite, microporous polycaprolactone nasal implant demonstrated proper mechanical support and thinness with excellent biocompatibility and surgical manipulability. Polycaprolactone may be a clinically biocompatible material for use in various craniofacial reconstructions in the future.