A novel bilayer polycaprolactone membrane for guided bone regeneration : combining electrospinning and emulsion templating

Guided bone regeneration is a common dental implant treatment where a barrier membrane (BM) is used between epithelial tissue and bone or bone graft to prevent the invasion of the fast-proliferating epithelial cells into the defect site to be able to preserve a space for infiltration of slower-growing bone cells into the periodontal defect site. In this study, a bilayer polycaprolactone (PCL) BM was developed by combining electrospinning and emulsion templating techniques. First, a 250 µm thick polymerised high internal phase emulsion (polyHIPE) made of photocurable PCL was manufactured and treated with air plasma, which was shown to enhance the cellular infiltration. Then, four solvent compositions were investigated to find the best composition for electrospinning a nanofibrous PCL barrier layer on PCL polyHIPE. The biocompatibility and the barrier properties of the electrospun layer were demonstrated over four weeks in vitro by histological staining. Following in vitro assessment of cell viability and cell migration, cell infiltration and the potential of PCL polyHIPE for supporting blood vessel ingrowth were further investigated using an ex-ovo chick chorioallantoic membrane assay. Our results demonstrated that the nanofibrous PCL electrospun layer was capable of limiting cell infiltration for at least four weeks, while PCL polyHIPE supported cell infiltration, calcium and mineral deposition of bone cells, and blood vessel ingrowth through pores

The Effect of Heat Treatment on Physical, Chemical and Structural Properties of Calcium Sulfate Based Scaffolds

3D printed calcium sulfate (CS) is a promising material for on custom bone substitutes. Since it dissolves easily in body fluids, manufactured samples require to being improved to reduce solubility.  The main aim of this study was reducing the dissolubility of CS based samples by using sintering and investigating the effect of heat treatment on their physical, chemical and structural properties. To observe the effect of heat treatment on samples, contact angles were measured, X-Ray diffraction analysis (XRD) was performed, and scanning electron microscope (SEM) micrographs were captured before and after the sintering process, and the results were compared. Furthermore, sintered and non-sintered samples were soaked in phosphate buffered saline (PBS) to observe the impact of sintering on the solubility of the material. Also, three different pore sized scaffolds were manufactured to test the limits of the 3D printer for manufacturing of scaffolds with open pores. Sintering process results in a volume reduction and according to SEM results, CS grains were fused together after heat treatment. Although non-sintered CS sample starts to dissolve in high rate and nearly 1/3 of the sample was at the bottom of the glass in a matter of minutes, sintering creates more rigid structure and there were not visible dissolution in PBS at the end of a week. The contact angle of samples cannot be measured, so it can be concluded that 3D printed material showed a super-hydrophilic property. XRD diagram suggested that there is not any new phase created in the printing and sintering processes except related hydrates of CS. As a result of the 3D printing, 500 µm, 750 µm and 1000 µm pore sized scaffolds were manufactured, successfully. However, it was seen that 500 µm pores could not be open by using depowdering after the printing process

3D Tissue Scaffold Printing On Custom Artificial Bone Applications

Production of defect-matching scaffolds is the most critical step in custom artificial bone applications. Three dimensional printing (3DP) is one of the best techniques particularly for custom designs on artificial bone applications because of the high controllability and design independency. Our long-term aim is to implant an artificial custom bone that is cultured with patient's own mesenchymal stem cells after determining defect architecture on patient's bone by using CT-scan and printing that defect-matching 3D scaffold with appropriate nontoxic materials. In this study, preliminary results of strength and cytotoxicity measurements of 3D printed scaffolds with modified calcium sulfate compositepowder (MCSCP) were presented. CAD designs were created and MCSCP were printed by a 3D printer (3DS, Visijet, PXL Core). Some samples were covered with salt solution in order to harden the samples. MCSCP and salt coated MCSCP were the two experimental groups in this study. Cytotoxicity and mechanical experiments were performed after surface examination withscanning electron microscope (SEM) and light microscope. Tension tests were performed for MCSCP and salt coated MCSCP samples. The 3D scaffolds were sterilized with ethylene oxide gas sterilizer, ventilated and conditioned with DMEM (10% FBS). L929 mouse fibroblast cells were cultured on scaffolds (3 repetitive) and cell viability was determined using MTT analysis. According to the mechanical results, the MCSCP group stands until average 71,305 N, while salt coated MCSCP group stands until 21,328N. Although the strength difference between two groups is statistically significant (p=0.001, Mann-Whitney U), elastic modulus is not (MCSCP=1,186Pa, salt coated MCSCP=1,169Pa, p=0.445). Cell viability (MTT analysis) results on day 1, 3, and 5 demonstrated thatscaffolds hadno toxic effect to the L929 mouse fibroblast cells. Consequently, 3D printed samples with MCSCP could potentially be a strong alternative (biocompatible) for current custom made scaffolds. Desired strength can be acquired with cell inoculation and cultivation of samples in a bioreactor for ossificatio

Engineering periodontal tissue interfaces using multiphasic scaffolds and membranes for guided bone and tissue regeneration

Periodontal diseases are one of the greatest healthcare burdens worldwide. The periodontal tissue compartment is an anatomical tissue interface formed from the periodontal ligament, gingiva, cementum, and bone. This multifaceted composition makes tissue engineering strategies challenging to develop due to the interface of hard and soft tissues requiring multiphase scaffolds to recreate the native tissue architecture. Multilayer constructs can better mimic tissue interfaces due to the individually tuneable layers. They have different characteristics in each layer, with modulation of mechanical properties, material type, porosity, pore size, morphology, degradation properties, and drug-releasing profile all possible. The greatest challenge of multilayer constructs is to mechanically integrate consecutive layers to avoid delamination, especially when using multiple manufacturing processes. Here, we review the development of multilayer scaffolds that aim to recapitulate native periodontal tissue interfaces in terms of physical, chemical, and biological characteristics. Important properties of multiphasic biodegradable scaffolds are highlighted and summarised, with design requirements, biomaterials, and fabrication methods, as well as post-treatment and drug/growth factor incorporation discussed

Development of Transvaginal Uterus Amputation Device for Laparoscopic Hysterectomies in Gynecologic Surgeries

Hysterectomy, that is removal of uterus, is one of the most common major operations in gynecologic surgeries. Laparoscopy technique is preferred in hysterectomy because of its advantages such as lower intra-operative blood loss, decreased surrounding tissue/organ damage, less operating time, lower postoperative infection and frequency of fever, shorter duration of hospitalization and post-operative returning time to normal activity. During total laparoscopic hysterectomy, first uterine vessels and ligaments are cauterized respectively, and then cervicovaginal connections are cauterized and coagulated to remove uterus completely. Uterine manipulators are used during laparoscopy to maximize the endoscopic vision of surgeons by moving related organs. However, conventional uterine manipulators have important drawbacks particularly to move uterus in three dimensions and to show cervicovaginal landmark during laparoscopic circular cauterization and amputation of the uterine cervix. A new transvaginal uterine manipulator may overcome these two important drawbacks of these currently available devices. For this reason, a3D scanned technique was used to get uterus sizes and computer aided design software is used in designing of the new manipulator and then 3D printer was used in prototyping. Special light emitting diodes (LEDs) were mounted on the cervical cap of the manipulator to guide light beams from inside of cervicovaginal tissue to abdominal cavity to facilitate the visualization of tissue landmarks. Moreover, performances of different caps and LED systems will be evaluated. Furthermore, after integration of self-cutting and self-suturing mechanisms into our system, final prototype will be produced by using titanium which is biologically and mechanically appropriate. Therefore, aim of this study was to design and produce a new uterine manipulator with three dimensional movements, LED illumination, self-cutting and self-suturing systems to facilitate laparoscopic hysterectom

DataSheet1_Gelatin-containing porous polycaprolactone PolyHIPEs as substrates for 3D breast cancer cell culture and vascular infiltration.docx

Tumour survival and growth are reliant on angiogenesis, the formation of new blood vessels, to facilitate nutrient and waste exchange and, importantly, provide a route for metastasis from a primary to a secondary site. Whilst current models can ensure the transport and exchange of nutrients and waste via diffusion over distances greater than 200 μm, many lack sufficient vasculature capable of recapitulating the tumour microenvironment and, thus, metastasis. In this study, we utilise gelatin-containing polymerised high internal phase emulsion (polyHIPE) templated polycaprolactone-methacrylate (PCL-M) scaffolds to fabricate a composite material to support the 3D culture of MDA-MB-231 breast cancer cells and vascular ingrowth. Firstly, we investigated the effect of gelatin within the scaffolds on the mechanical and chemical properties using compression testing and FTIR spectroscopy, respectively. Initial in vitro assessment of cell metabolic activity and vascular endothelial growth factor expression demonstrated that gelatin-containing PCL-M polyHIPEs are capable of supporting 3D breast cancer cell growth. We then utilised the chick chorioallantoic membrane (CAM) assay to assess the angiogenic potential of cell-seeded gelatin-containing PCL-M polyHIPEs, and vascular ingrowth within cell-seeded, surfactant and gelatin-containing scaffolds was investigated via histological staining. Overall, our study proposes a promising composite material to fabricate a substrate to support the 3D culture of cancer cells and vascular ingrowth.</p