Development of 3D PCL microsphere/TiO\u3csub\u3e2\u3c/sub\u3e nanotube composite scaffolds for bone tissue engineering

In this research, the three dimensional porous scaffolds made of a polycaprolactone (PCL) microsphere/TiO2 nanotube (TNT) composite was fabricated and evaluated for potential bone substitute applications. We used a microsphere sintering method to produce three dimensional PCL microsphere/TNT composite scaffolds. The mechanical properties of composite scaffolds were regulated by varying parameters, such as sintering time, microsphere diameter range size and PCL/TNT ratio. The obtained results ascertained that the PCL/TNT (0.5 wt%) scaffold sintered at 60 °C for 90 min had the most optimal mechanical properties and an appropriate pore structure for bone tissue engineering applications. The average pore size and total porosity percentage increased after increasing the microsphere diameter range for PCL and PCL/TNT (0.5 wt%) scaffolds. The degradation rate was relatively high in PCL/TNT (0.5 wt%) composites compared to pure PCL when the samples were placed in the simulated body fluid (SBF) for 6 weeks. Also, the compressive strength and modulus of PCL and PCL/TNT (0.5 wt%) composite scaffolds decreased during the 6 weeks of storage in SBF. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay and alkaline phosphates (ALP) activity results demonstrated that a generally increasing trend in cell viability was observed for PCL/TNT (0.5 wt%) scaffold sintered at 60 °C for 90 min compared to the control group. Eventually, the quantitative RT-PCR data provided the evidence that the PCL scaffold containing TiO2 nanotube constitutes a good substrate for cell differentiation leading to ECM mineralization

Efficacy of group obstetric consultation in mild to moderate anxiety of pregnancy

Anxiety is a common mental disorder of pregnancy leading to adverse maternal and fetal pregnancy outcomes. Hence, preparation of effective approaches for reduction of anxiety is an issue of importance. Accordingly, this study was performed to determine the efficacy of group obstetric consultation on anxiety control in pregnant women in non-severe cases. In this randomized clinical trial, 90 pregnant women attending to a Health Care Center in Tehran, Iran from April 2010 to March 2012 with first pregnancy aging from 18 to 35 years and gestational age of eight to eighteen weeks were evaluated. They were randomly assigned into consultation and control groups. The consultation group was designed according to the different needs of pregnancy for five sessions in five weeks (each session 60 to 90 minutes) and the control group only received routine perinatal care. There was statistically significant difference between after-intervention scores in anxiety state (P=0.014); but the anxiety trait showed no difference (P=0.19). Also the changes in trait anxiety scores was more in consultation group compared with control group (P=0.002) that was also seen for anxiety state scores (P=0.0001). Totally, it may be concluded that group consultation is effective in reduction of state and trait anxiety in pregnant women with non-severe non-pathological cases of anxiety

Collagenous Matrix Supported by A 3D-Printed Scaffold for Osteogenic Differentiation of Dental Pulp Cells

Objective A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs). Methods The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing. Results The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity. Significance The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration

Effects of Different Perfusing Routes through The Portal Vein, Hepatic Vein, and Biliary Duct on Whole Rat Liver Decellularization

Objective: Organ transplantation is the last therapeutic choice for end-stage liver failure, which is limited by the lack ofsufficient donors. Decellularized liver can be used as a suitable matrix for liver tissue engineering with clinical applicationpotential. Optimizing the decellularization procedure would obtain a biological matrix with completely removed cellularcomponents and preserved 3-dimensional structure. This study aimed to evaluate the decellularization efficacy throughthree anatomical routes. Materials and Methods: In this experimental study, rat liver decellularization was performed through biliary duct (BD),portal vein (PV), and hepatic vein (HV); using chemical detergents and enzymes. The decellularization efficacy wasevaluated by measurement of DNA content, extracellular matrix (ECM) total proteins, and glycosaminoglycans (GAGs).ECM preservation was examined by histological and immunohistochemical (IHC) staining and scanning electronmicroscopy (SEM). Scaffold biocompatibility was tested by the MTT assay for HepG2 and HUVEC cell lines. Results: Decellularization through HV and PV resulted in a transparent scaffold by complete cell removal, while the BDroute produced an opaque scaffold with incomplete decellularization. H&E staining confirmed these results. MaximumDNA loss was obtained using 1% and 0.5% sodium dodecyl sulfate (SDS) in the PV and HV groups and the DNAcontent decreased faster in the HV group. At the final stages, the proteins excreted in the HV and PV groups weresignificantly less than the BD group. The GAGs level was diminished after decellularization, especially in the PV andHV groups. In the HV and PV groups the collagen amount was significantly more than the BD group. The IHC and SEMimages showed that the ECM structure was preserved and cellular components were entirely removed. MTT assayshowed the biocompatibility of the decellularized scaffold. Conclusion: The results revealed that the HV is a more suitable route for liver decellularization than the PV and BD

Efficacy of the Biomaterials 3 wt%-nanostrontium-hydroxyapatite-enhanced Calcium Phosphate Cement (nanoSr-CPC) and nanoSr-CPC-incorporated Simvastatin-loaded Poly(lactic-co-glycolic-acid) Microspheres in Osteogenesis Improvement

Aims The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test experimental study was to (1) create a 3 wt%-nanostrontium hydroxyapatite-enhanced calcium phosphate cement (Sr-HA/CPC) for increasing bone formation and (2) creating a simvastatin-loaded poly(lactic-co-glycolic acid) (SIM-loaded PLGA) microspheres plus CPC composite (SIM-loaded PLGA + nanostrontium-CPC). The third goal was the extensive assessment of multiple in vitro and in vivo characteristics of the above experimental explorative products in vitro and in vivo (animal and surgical studies). Methods and results pertaining to Sr-HA/CPC Physical and chemical properties of the prepared Sr-HA/CPC were evaluated. MTT assay and alkaline phosphatase activities, and radiological and histological examinations of Sr-HA/CPC, CPC and negative control were compared. X-ray diffraction (XRD) indicated that crystallinity of the prepared cement increased by increasing the powder-to-liquid ratio. Incorporation of Sr-HA into CPC increased MTT assay (biocompatibility) and ALP activity (P \u3c 0.05). Histomorphometry showed greater bone formation after 4 weeks, after implantation of Sr-HA/CPC in 10 rats compared to implantations of CPC or empty defects in the same rats (n = 30, ANOVA P \u3c 0.05). Methods and results pertaining to SIM-loaded PLGA microspheres + nanostrontium-CPC composite After SEM assessment, the produced composite of microspheres and enhanced CPC were implanted for 8 weeks in 10 rabbits, along with positive and negative controls, enhanced CPC, and enhanced CPC plus SIM (n = 50). In the control group, only a small amount of bone had been regenerated (localized at the boundary of the defect); whereas, other groups showed new bone formation within and around the materials. A significant difference was found in the osteogenesis induced by the groups sham control (16.96 ± 1.01), bone materials (32.28 ± 4.03), nanostrontium-CPC (24.84 ± 2.6), nanostrontium-CPC-simvastatin (40.12 ± 3.29), and SIM-loaded PLGA + nanostrontium-CPC (44.8 ± 6.45) (ANOVA P \u3c 0.001). All the pairwise comparisons were significant (Tukey P \u3c 0.01), except that of nanostrontium-CPC-simvastatin and SIM-loaded PLGA + nanostrontium-CPC. This confirmed the efficacy of the SIM-loaded PLGA + nanostrontium-CPC composite, and its superiority over all materials except SIM-containing nanostrontium-CPC

Enhancing Cell Seeding and Osteogenesis of MSCs on 3D Printed Scaffolds Through Injectable BMP2 Immobilized ECM-Mimetic Gel

Objective Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices. These matrices were designed to enhance cell seeding efficiency of mesenchymal stem cells (MSCs) as well as improve their osteogenic differentiation through immobilized bone morphogenic protein 2 (BMP2) to be used for personalized bone regeneration. Methods A 3D gel based on heparin-conjugated collagen matrix capable of immobilizing recombinant human bone morphogenic protein 2 (BMP2) was synthesized. Isolated dental pulp Mesenchymal stem cells (MSCs) were then encapsulated into the bone ECM microenvironment to efficiently and uniformly seed a bioactive ceramic-based scaffold fabricated using additive manufacturing technique. The designed 3D cell-laden constructs were comprehensively investigated trough in vitro assays and in vivo study. Results In-depth rheological characterizations of heparin-conjugated collagen gel revealed that elasticity of the matrix is significantly improved compared with freely incorporated heparin. Investigation of the MSCs laden collagen-heparin hydrogels revealed their capability to provide spatiotemporal bioavailability of BMP2 while suppressing the matrix contraction over time. The in vivo histology and real-time polymerase chain reaction (qPCR) analysis showed that the designed construct supported the osteogenic differentiation of MSCs and induced the ectopic bone formation in rat model. Significance The presented hybrid constructs combine bone ECM chemical cues with mechanical function providing an ideal 3D microenvironment for patient-specific bone tissue engineering and cell therapy applications. The implemented methodology in design of ECM-mimetic 3D matrix capable of immobilizing BMP2 to improve seeding efficiency of customized scaffolds can be exploited for other bioactive molecules

Critical-Sized Bone Defects Regeneration Using a Bone-Inspired 3D Bilayer Collagen Membrane in Combination with Leukocyte and Platelet-Rich Fibrin Membrane (L-PRF): An \u3cem\u3eIn Vivo\u3c/em\u3e Study

Objectives We aim to develop a 3D-bilayer collagen (COL) membrane reinforced with nano beta-tricalcium-phosphate (nβ-TCP) particles and to evaluate its bone regeneration in combination with leukocyte-platelet-rich fibrin (L-PRF) in vivo. Background data L-PRF has exhibited promising results as a cell carrier in bone regeneration in a number of clinical studies, however there are some studies that did not confirm the positive results of L-PRF application. Methods Mechanical & physiochemical characteristics of the COL/nβ-TCP membrane (1/2 & 1/4) were tested. Proliferation and osteogenic differentiation of seeded cells on bilayer collagen/nβ-TCP thick membrane was examined. Then, critical-sized calvarial defects in 8 white New Zealand rabbits were filled with either Col, Col/nβ-TCP, Col/nβ-TCP combined with L-PRF membrane, or left empty. New bone formation (NBF) was measured histomorphometrically 4 & 8 weeks postoperatively. Results Compressive modulus increases while porosity decreases with higher β-TCP concentrations. Mechanical properties improve, with 89 % porosity (pore size ∼100 μm) in the bilayer-collagen/nβ-TCP membrane. The bilayer design also enhances the proliferation and ALP activity. In vivo study shows no significant difference among test groups at 4 weeks, but Col/nβ-TCP + L-PRF demonstrates more NBF compared to others (P \u3c 0.05) after 8 weeks. Conclusion The bilayer-collagen/nβ-TCP thick membrane shows promising physiochemical in vitro results and significant NBF, as ¾ of the defect is filled with lamellar bone when combined with L-PRF membrane

Design and Fabrication of Biodegradable Tissue Adhesive Using Albumin Nanoparticles and Polypyrrole as a Suture Substitute in Surgery and Trauma

Background and Aim: Tissue adhesives are increasingly used instead of sutures or staples to close wounds in modern medicine. It seems that use of tissue adhesives can lead to faster and easier closure of the surgical wounds in comparison to sutures. Moreover, tissue glues have a wide application in the fields of tissue engineering and drug delivery systems. Bio-glue which is a widely used bioadhesive in surgery contains bovine serum albumin and glutaraldehyde, but it has significant tissue toxicity due to the high percentage of glutaraldehyde. Adhesive biocompatibility may improve by using albumin nanoparticles along with less toxic cross-linkers such as polypyrrole. Materials and methods:  Albumin nanoparticles were prepared by coacervation method and then, polypyrrole and glutaraldehyde in different proportions were used to prepare the bioadhesive. The properties of nanoparticles were examined by DLS, zeta potential analysis, FT-IR spectrum, and scanning electron microscopy. The effects of pH and concentration of albumin nanoparticles on gelation time were analyzed and the cytotoxicity of the adhesive was investigated by the MTT technique. Results:  Among the prepared composites, the shortest gelation time was 20 seconds which belonged to the composite containing both crosslinking agents (pyrrole and glutaraldehyde 3%). The results of MTT assay showed that by reducing the percentage of glutaraldehyde, the toxicity of the adhesive significantly decreased (P <0.0001) compared to the toxicity of adhesive containing 10% glutaraldehyde. Conclusion: Adhesive prepared by use of polypyrrole and 3% glutaraldehyde had a shorter gelation time and greater biocompatibility than the adhesive containing 10% glutaraldehyde. Therefore, it has the potential to replace other adhesives in the medical clinics

Periodontal Complex Regeneration: From Hard to Soft Tissue Interface

Periodontal disease, as a prevalent public health problem, could leads to bone resorption and ultimate tooth loss. Due to the nature of interfacial hard to soft tissue structure in periodontal complex, its wound healing is more complicated than normal oral mucosa after surgical procedures. To improve the success rate of surgical regenerative therapies in periodontal tissue, having insight to the natural tissue dissimilarities and biomechanical concepts in periodontium is crucial. Optimal periodontal regeneration contains restoration of the all three components of periodontal ligament, cementum and alveolar bone. In recent decades, many researchers have developed and characterized several strategies according to interfacial tissue engineering for periodontal regeneration. In the current review, the bio-clinical principles and current strategies for periodontal regeneration and future perspective are discussed

Developing a pro-angiogenic placenta derived amniochorionic scaffold with two exposed basement membranes as substrates for cultivating endothelial cells

Decellularized and de-epithelialized placenta membranes have widely been used as scaffolds and grafts in tissue engineering and regenerative medicine. Exceptional pro-angiogenic and biomechanical properties and low immunogenicity have made the amniochorionic membrane a unique substrate which provides an enriched niche for cellular growth. Herein, an optimized combination of enzymatic solutions (based on streptokinase) with mechanical scrapping is used to remove the amniotic epithelium and chorion trophoblastic layer, which resulted in exposing the basement membranes of both sides without their separation and subsequent damages to the in-between spongy layer. Biomechanical and biodegradability properties, endothelial proliferation capacity, and in&nbsp;vivo pro-angiogenic capabilities of the substrate were also evaluated. Histological staining, immunohistochemistry (IHC) staining for collagen IV, and scanning electron microscope demonstrated that the underlying amniotic and chorionic basement membranes remained intact while the epithelial and trophoblastic layers were entirely removed without considerable damage to basement membranes. The biomechanical evaluation showed that the scaffold is suturable. Proliferation assay, real-time polymerase chain reaction for endothelial adhesion molecules, and IHC demonstrated that both side basement membranes could support the growth of endothelial cells without altering endothelial characteristics. The dorsal skinfold chamber animal model indicated that both side basement membranes could promote angiogenesis. This bi-sided substrate with two exposed surfaces for cultivating various cells would have potential applications in the skin, cardiac, vascularized composite allografts, and microvascular tissue engineering