Solvent Casting Particulate Leaching Research Articles

Synthetic strategy for the production of electrically polarized polyvinylidene fluoride-trifluoroethylene-co-polymer osseo-functionalized with hydroxyapatite scaffold.

The physiological mechanism of bone tissue regeneration is intricately organized and involves several cell types, intracellular, and extracellular molecular signaling networks. To overcome the drawbacks of autografts and allografts, a number of synthetically produced scaffolds have been manufactured by integrating ceramics, polymers, and their hybrid-composites. Considering the fact that natural bone is composed primarily of collagen and hydroxyapatite, ceramic-polymer composite materials seem to be the most viable alternative to bone implants. Here, in this experimental study, copolymer PVDF-TrFE has been amalgamated with HA ceramics to produce composite scaffolds as bone implants. In order to fabricate PVDF-TrFE-HA (polyvinylidene fluoride-trifluoroethylene-hydroxyapatite) composite scaffolds, solvent casting-particulate leaching technique was devised. Two scaffold specimens were produced, with different PVDF-TrFE and HA molar ratios (70:30 and 50:50), and then electrically polarized to observe the subsequent polarization impact on the tissue growth and the suppression of bacterial cell proliferation. Both the specimens underwent characterization to analyze their biocompatibility and bactericidal activities. The bacterial culture of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) bacteria on the composites was studied to understand the antibacterial characteristics. Moreover, MG63 cells cultured on these as-formed composites provided information about osteogenesis. Improved osteogenesis and antibacterial efficacy were observed on both the composites. However, the composite with 70 wt% PVDF-TrFE and 30 wt% HA showed a higher bactericidal effect as well as osteogenesis. It was found that PVDF-TrFE-HA-based biomaterials have the potential for bone tissue engineering applications.

Star-PCL shape memory polymer (SMP) scaffolds with tunable transition temperatures for enhanced utility.

Thermoresponsive shape memory polymers (SMPs) prepared from UV-curable poly(ε-caprolactone) (PCL) macromers have the potential to create self-fitting bone scaffolds, self-expanding vaginal stents, and other shape-shifting devices. To ensure tissue safety during deployment, the shape actuation temperature (i.e., the melt transition temperature or Tm of PCL) must be reduced from ∼55 °C that is observed for scaffolds prepared from linear-PCL-DA (Mn ∼ 10 kg mol-1). Moreover, increasing the rate of biodegradation would be advantageous, facilitating bone tissue healing and potentially eliminating the need for stent retrieval. Herein, a series of six UV-curable PCL macromers were prepared with linear or 4-arm star architectures and with Mns of 10, 7.5, and 5 kg mol-1, and subsequently fabricated into six porous scaffold compositions (10k, 7.5k, 5k, 10k★, 7.5k★, and 5k★) via solvent casting particulate leaching (SCPL). Scaffolds produced from star-PCL-tetraacrylate (star-PCL-TA) macromers produced pronounced reductions in Tm with decreased Mnversus those formed with the corresponding linear-PCL-diacrylate (linear-PCL-DA) macromers. Scaffolds were produced with the desired reduced Tm profiles: 37 °C < Tm < 55 °C (self-fitting bone scaffold), and Tm ≤ 37 °C (self-expanding stent). As macromer Mn decreased, crosslink density increased while % crystallinity decreased, particularly for scaffolds prepared from star-PCL-TA macromers. While shape memory behavior was retained and radial expansion pressure increased, this imparted a reduction in modulus but with an increase in the rate of degradation.

Investigation on Electrospun and Solvent-Casted PCL-PLGA Blends Scaffolds Embedded with Induced Pluripotent Stem Cells for Tissue Engineering.

The design, production, and characterisation of tissue-engineered scaffolds made of polylactic-co-glycolic acid (PLGA), polycaprolactone (PCL) and their blends obtained through electrospinning (ES) or solvent casting/particulate leaching (SC) manufacturing techniques are presented here. The polymer blend composition was chosen to always obtain a prevalence of one of the two polymers, in order to investigate the contribution of the less concentrated polymer on the scaffolds' properties. Physical-chemical characterization of ES scaffolds demonstrated that tailoring of fibre diameter and Young modulus (YM) was possible by controlling PCL concentration in PLGA-based blends, increasing the fibre diameter from 0.6 to 1.0 µm and reducing the YM from about 22 to 9 MPa. SC scaffolds showed a "bubble-like" topography, caused by the porogen spherical particles, which is responsible for decreasing the contact angles from about 110° in ES scaffolds to about 74° in SC specimens. Nevertheless, due to phase separation within the blend, solvent-casted samples displayed less reproducible properties. Furthermore, ES samples were characterised by 10-fold higher water uptake than SC scaffolds. The scaffolds suitability as iPSCs culturing support was evaluated using XTT assay, and pluripotency and integrin gene expression were investigated using RT-PCR and RT-qPCR. Thanks to their higher wettability and appropriate YM, SC scaffolds seemed to be superior in ensuring high cell viability over 5 days, whereas the ability to maintain iPSCs pluripotency status was found to be similar for ES and SC scaffolds.

Dielectric, Electrical Conductivity, and Thermal Stability Studies of Cellulosic Fibers Reinforced Polylactic Acid Composites

ABSTRACT In this study, biodegradable polylactic acid (PLA) composites were reinforced with three different natural fibers, were bamboo (BF), sugarcane (SF), and banana pseudostem (BPF) fibers, and prepared at different loadings (10, 20, and 30 wt.%). The solvent casting particulate leaching method was implemented to produce porous composites, and salt was used as the particulate material. The dielectric properties of the PLA/BF, PLA/SF, and PLA/BF composites were studied for different loadings of cellulosic fibers. The composites were observed using scanning electron microscopy (SEM), and the PLA composites with 30 wt.% filler content were analyzed using Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). According to the dielectric tests, all PLA/BF, PLA/SF, and PLA/BPF composites have low dielectric constants and dielectric loss. The PLA/BF composites exhibited the highest dielectric constant, dielectric loss, and electrical conductivity, followed by the PLA/BF and PLA/SF composites. The morphology of the composites showed their porous structure. The FTIR spectra showed the main constituents presented in the composites, and the PLA/BF showed higher thermal stability than the other composites.

A study on the development of scaffold fabrication using citric acid polyester – nanohydroxyapatite composite

ABSTRACT. Nano hydroxyapatite (n-HAp) and its composites have shown a great development in the field of tissue regeneration and in controlled drug delivery due to its good biocompatibility and bioactivity behavior. Furthermore, HAp-based nanocomposites enhance mechanical properties. These synthetic HAp nanocomposites can also be tailored to fabricate scaffold with controlled porosity which facilitate the growth of the cell in the field of tissue engineering. In this paper, we focus on the synthesis of nano hydroxyapatite (n-HAp) by sol-gel method. The synthesized nano powders were calcined at 500 oC and characterized by FT-IR, XRD and TEM. We have also described the synthesis of citric acid-based polyester by melt polycondensation method without adding catalyst. The monomers used were citric acid, 1,6-hexane diol and sebacic acid. The corresponding synthesized n-HAp/polyester composite have potential application in soft tissue engineering. The structures of polyester and its nanocomposite were studied by FT-IR and 1H NMR spectral studies. The thermal and mechanical properties of polyester, composites and cytotoxicity activity (MTT assay) using vero cells were also studied. Porous scaffold of the nano HAp/Polyester was fabricated by solvent-casting particulate leaching technique which is useful in the development of tissue engineering applications. SEM and TEM studies were carried out for nano HAp, polyester, composites and scaffold.&#x0D; &#x0D; KEY WORDS: Cytotoxicity, Polycondensation, Sol-gel, Solvent-casting, Tissue engineering&#x0D; Bull. Chem. Soc. Ethiop. 2022, 36(4), 923-934. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v36i4.17

MBG/ PGA-PCL composite scaffolds provide highly tunable degradation and osteogenic features

It remains a challenge to achieve satisfactory balance between biodegradability and osteogenic capacity in biosynthetic bone grafts. In this study, we aimed to address this challenge by incorporating mesoporous bioactive glass (MBG) into poly(caprolactone-co-glycolide) (PGA-PCL) at gradient ratios. MBG/PGA-PCL (PGC/M) scaffolds with MBG incorporation ratio at 0, 10%, 25% and 40% (PGC/M0-40) were synthesized using a modified solvent casting-particulate leaching method, and their physiochemical and biological properties were comprehensively evaluated. PGC/M scaffolds exhibited highly perforated porous structure with a large-pore size of 300–450 μm, with ordered MBGs of around 6.0 nm mesopores size uniformly dispersed. The increase in MBG incorporation ratio significantly improved the scaffold surface hydrophilicity, apatite-formation ability and pH stability, increased the weight loss rate while insignificantly influenced the molecular chains degradation of PGA-PCL component, and facilitated the attachment, spreading, viability and proliferation of rat bone marrow stromal cells (rBMSCs) on scaffolds. Moreover, rBMSCs cultured on PGC/M10-40 scaffolds demonstrated enhanced ALP activity and osteogenesis-related gene expression in a MBG dose-dependent manner as compared with those cultured on PGC/M0 scaffolds. When implanted to the rat cranial bone defect, PGC/M25 and PGC/M40 scaffolds induced significantly better bone repair as compared to PGC/M0 and PGC/M10 scaffolds. Besides, the biodegradability of PGC/M scaffolds correlated with the MBG incorporation ratio. These data suggested this novel PGC/M scaffolds as promising bone repair biomaterial with highly tunable hydrophilicity, bioactivity, cytocompatibility, osteogenic activity as well as biodegradability.

Fabrication of calcium hydroxyapatite incorporated polyurethane-graphene oxide nanocomposite porous scaffolds from poly (ethylene terephthalate) waste: A green route toward bone tissue engineering

Biodegradable porous polymeric scaffolds were prepared from Polyurethane (PU) for the purpose of osteoblast cells regeneration to utilize in the restoration of damage bone tissues. The PU was synthesized from post-consumer discarded Poly ethylene terephthalate (PET) waste by glycolysis method. The produced monomer bis(2-hydroxyethyl) terephthalate (BHET) was reacted with diisocynate and there after with selected chain extender glycol. In this study, graphene oxide (GO) was used as a polyol in the esterification reaction. Also, the GO acted as a nano filler that imparted the strength to the system along with antimicrobial activity. The various composites of PU-GO/hydroxyapatite (Hap) were prepared by varying the content of GO/Hap from 0 to 10% of total weight of the composite. The porous scaffolds were developed from composites by solvent casting/particulate leaching (SCPL) method. Furthermore, the physical, morphological, elemental, mechanical and thermo-mechanical properties of scaffolds were analyzed. The prepared scaffolds were subjected to U2OS human embryonic osteoblast cell line to analyze the response of osteoblast cells. In vitro studies such as cell growth, degradation, and cyto-compatibility were carried out. The outcomes of this study have asserted that the developed scaffolds are compatible for U2OS cells growth, thus can be used for bone tissue regeneration.

Investigation of Physico-mechanical Behavior, Permeability and Wall Shear Stress of Porous HA/PMMA Composite Bone Scaffold

Hydroxyapatite (HA)-based composite bone scaffolds are developed using solvent casting particulate leaching technique by varying the weight percentages of HA from 50 to 70% (w/w) in polymethyl methacrylate matrix. The chemical properties of the developed scaffolds are investigated by XRD analysis which shows the presence of crystalline HA and traces of β-TCP in the scaffolds. The microstructure of the scaffolds is studied by the SEM micrographs, which show porous morphology with an average pore size of 119 ± 18–148 ± 23 µm and a maximum pore size of 148 ± 23 µm for HA 50 scaffold. The highest porosity of 75 ± 2.0% is recorded for HA 50 scaffold by conducting liquid displacement test and a maximum compressive strength of 6.26 ± 0.53 MPa is recorded for HA 60 scaffold by performing uniaxial compression test of the scaffolds. The permeability and wall shear stress (WSS) of the scaffolds are investigated by computational fluid dynamics (CFD). The CFD analysis is performed in a fluid domain developed by Boolean operations on the CAD model of the scaffold developed using micro-computed tomography-based 3D image acquisition technique by Mimics V1. Results show that the permeability increases and WSS decreases with an increase in the porosity of the scaffolds. However, both permeability and WSS obtained for the developed scaffolds are within the limit prescribed for the growth of bone tissues. It is concluded that scaffolds with 60 wt% of HA exhibit the best combination of porosity, permeability and compressive strength making it suitable for bone tissue engineering applications.

Porous Scaffolds of Poly(lactic-co-glycolic acid) and Mesoporous Hydroxyapatite Surface Modified by Poly(γ-benzyl-l-glutamate) (PBLG) for in Vivo Bone Repair.

Three-dimensional (3D) composite porous scaffolds containing hydroxyapatite (HA) and polymer matrix showed wide applications in bone repair because of their improved biocompatibility, bioactivity, and mechanical properties in our previous studies. In this work, mesoporous hydroxyapatite (MHA) surface-modified by poly(γ-benzyl-l-glutamate) (PBLG) with different amounts (from 11 to 50 wt %) was synthesized by the in situ ring opening polymerization of γ-benzyl-l-glutamate N-carboxy anhydride (BLG-NCA) and then PBLG-g-MHA/PLGA composite films were prepared to illustrate the biological performance of the composites. Furthermore, porous scaffolds of PBLG-g-MHA/PLGA were fabricated through modified solvent casting/particulate leaching (SC/PL) method to demonstrate the ability of in vivo bone defect repair. In vitro cytological assay indicated that enhanced cell expansion on PBLG-g-MHA/PLGA with 11 wt % PBLG amounts and improved osteogenic differentiation on the composites with 33 and 50 wt % PBLG amounts were achieved. And the porous scaffolds exhibited high porosity and interconnected pores. Results of the in vivo rabbit radius defect repair indicated that rapid mineralization and new bone formation could be observed on the composites with 22 and 33 wt % PBLG. This study revealed that PBLG-g-MHA/PLGA composites might have potential applications in clinical bone repair.

Development of bone scaffold using Puntius conchonius fish scale derived hydroxyapatite: Physico-mechanical and bioactivity evaluations

Naturally derived Hydroxyapatite (HAp) from fish scale is finding wide applications in the development of bone scaffold to promote bone regeneration. But porous HAp scaffold is fragile in nature making it unsuitable for bone repair or replacement applications. Thus, it is essential to improve the mechanical property of HAp scaffolds while retaining the interconnected porous structure for tissue ingrowth in vivo. In this study solvent casting particulate leaching technique is used to develop novel Puntius conchonius fish scale derived HAp bone scaffold by varying the wt.% of the HAp from 60 to 80% in PMMA matrix. Physico-chemical, mechanical, structural and bioactive properties of the developed scaffolds are investigated. The obtained results indicate that HAp-PMMA scaffold at 70 wt % HAp loading shows optimal properties with 7.26 ± 0.45 MPa compressive strength, 75 ± 0.8% porosity, 8.0 ± 0.68% degradation and 190 ± 11% water absorption. The obtained results of the scaffold can meet the physiological demands to guide bone regeneration. Moreover, in vitro bioactivity analysis also confirms the formation of bone like apatite in the scaffold surface after 28 days of SBF immersion. Thus, the developed scaffold has the potential to be effectively used in bone tissue engineering applications.

Prechondrogenic ATDC5 cell response to graphene/multi-walled carbon nanotube-containing porous polycaprolactone biocomposite scaffolds

In the study graphene and multi- walled carbon nanotube (MWCNT) - containing polycaprolactone (PCL) scaffolds were prepared by solvent casting-particulate leaching method for cartilage tissue engineering applications. Graphene nanopowders or MWCNTs were added to the system at different concentrations namely 1, 3, 5 and 10 wt%. Mechanical, thermal and electrical properties of the scaffolds were measured as a function of additive concentration. Response of prechondrogenic ATDC5 cells seeded on the composite constructs were tested using XTT method and live-dead cell viability assay. Alkaline phosphatase activity of the cells was also tested to investigate differentiation behaviour. Results showed that electrically conductive composite scaffolds prepared in the study have potential to be used in tissue engineering.

Preparation and characterization of a piezoelectric poly (vinylidene fluoride)/nanohydroxyapatite scaffold capable of naproxen delivery

Piezoelectric polymers are of great interest because of their ability to produce temporary surface electric charge, which can have a positive impact on the growth, attachment and proliferation of osteoblastic cells. The aim of this study was to combine potential osteoinductive properties of piezoelectric PVDF with the excellent bioactivity of nHA. In this regard, PVDF/nHA composite scaffolds were fabricated via a solvent casting/particulate leaching (SC/PL) method. The composite scaffold at 5 wt% nHA was annealed for 5 h at 60 °C and 90 °C in order to induce α to β phase transformation. Naproxen (NAP) was chosen as a reference drug and was complexed with beta-cyclodextrin (βCD) to form an inclusion complex (NAP-βCD-IC). Both NAP and NAP-βCD-IC were incorporated into PVDF solution during the fabrication process. The results showed that pore size and porosity both increased with the addition of nHA up to 5 wt%. The compressive modulus and strength of the scaffolds was increased with increasing nHA content in the composite. Fourier transform infrared (FTIR) spectroscopy confirmed increased β phase content due to annealing, and a higher increment was achieved for samples annealed at 90 °C. Superior cell viability was observed in the sample with a higher amount of piezoelectric β phase compared with the as-prepared sample and the sample annealed at 60 °C. The release profile of NAP from the PVDF/nHA composite scaffold showed that the formation of NAP-βCD inclusion complexes increased the rate and amount of NAP release from the scaffold.

Effect of Modified Solvent Casting/Particulate Leaching (SCPL) Technique on the Properties of Bioactive Glass Reinforced Polyurethane Scaffold for Biomedical Applications

Effect of Modified Solvent Casting/Particulate Leaching (SCPL) Technique on the Properties of Bioactive Glass Reinforced Polyurethane Scaffold for Biomedical Applications

Development of solvent-casting particulate leaching (SCPL) polymer scaffolds as improved three-dimensional supports to mimic the bone marrow niche

The need for new approaches to investigate ex vivo the causes and effects of tumor and to achieve improved cancer treatments and medical therapies is particularly urgent for malignant pathologies such as lymphomas and leukemias, whose tissue initiator cells interact with the stroma creating a three-dimensional (3D) protective environment that conventional mono- and bi-dimensional (2D) models are not able to simulate realistically. The solvent-casting particulate leaching (SCPL) technique, that is already a standard method to produce polymer-based scaffolds for bone tissue repair, is proposed here to fabricate innovative 3D porous structures to mimic the bone marrow niche in vitro. Two different polymers, namely a rigid polymethyl methacrylate (PMMA) and a flexible polyurethane (PU), were evaluated to the purpose, whereas NaCl, in the form of common salt table, resulted to be an efficient porogen. The adoption of an appropriate polymer-to-salt ratio, experimentally defined as 1:4 for both PMMA and PU, gave place to a rich and interconnected porosity, ranging between 82.1 vol% and 91.3 vol%, and the choice of admixing fine-grained or coarse-grained salt powders allowed to control the final pore size. The mechanical properties under compression load were affected both by the polymer matrix and by the scaffold's architecture, with values of the elastic modulus indicatively varying between 29 kPa and 1283 kPa. Preliminary tests performed with human stromal HS-5 cells co-cultured with leukemic cells allowed us to conclude that stromal cells grown associated to the supports keep their well-known protective and pro-survival effect on cancer cells, indicating that these devices can be very useful to mimic the bone marrow microenvironment and therefore to assess the efficacy of novel therapies in pre-clinical studies.

Improved osteogenic differentiation of umbilical cord blood MSCs using custom made perfusion bioreactor

Background3D cell culture is an appropriate method to develop engineered bone tissue, where different bioreactors have been designed to mitigate the challenges in 3D culture. Currently, we tailored a perfusion reactor to witness human mesenchymal stem cells (MSCs) proliferation and differentiation over polylactic acid-polyethylene glycol (PLA/PEG) composite scaffolds. MethodsThe composite scaffolds with different weight ratios of PLA and PEG were prepared using solvent casting-particulate leaching technique. Human umbilcal card blood MSCs were cultured under dynamic and static conditions to elucidate the role of dynamic fluid flow in osteogenesis of MSCs. ResultsThe human MSCs distribution over the scaffolds was confirmed with fluorescent microscopy. Alkaline phosphatase (ALP), calcium mineralization, and collagen formation were found to be higher in PLA90 scaffolds than PLA100 and PLA75. PLA90 scaffolds with better cell adhesion/proliferartion were considered for bioreactor studies and they exhibited enhanced ALP, Ca+2 mineralization and collagen formation under dynamic perfusion than static culture. We further confirmed our observation by looking at expression levels of osteogenic marker (Runx2 and osteonectin) in differentiated MSCs subjected to perfusion culture compared to static culture. ConclusionThe results of the current investigation once again proves that dynamic perfusion cultures improve the osteogenic differentiation of MSCs over hybrid polymer scaffolds (PLA90) for effective bone regeneration.

Effect of pore architecture on osteoblast adhesion and proliferation on hydroxyapatite/poly(D,L) lactic acid-based bone scaffolds

The fabrication of three-dimensional (3D) scaffolds with an optimal pore architecture (e.g., pore size and porosity) that effectively promotes cellular activity on scaffold surfaces is of great interest in bone tissue engineering. In this work, three various 3D hydroxyapatite/poly(D,L)-lactic acid (HAp/PDLLA) scaffolds with different values of HAp to PDLLA in weight percent (0, 10, and 30%) were fabricated by applying a solvent casting–particulate leaching technique. Chloroform was used as a casting solvent to investigate the effects of pore architecture on cellular adhesion, distribution, and proliferation on the fabricated scaffolds. These scaffolds were characterized through field-emission scanning electron microscopy, X-ray diffraction, and liquid substitution to determine their structure, morphological characteristics, pore sizes, and porosity. Cell proliferation, adhesion, and distribution on these scaffolds were evaluated through in vitro tests with human osteoblast MG 63 cell line. Results showed that pore size and porosity greatly affected the proliferation, adhesion, and distribution of MG 63 cells on the fabricated scaffolds. Mean pore sizes ranging from 177 to 245 µm and porosities varying from 76 to 83% were optimal for cell proliferation and adhesion on these scaffolds. Among the fabricated scaffolds, 3D HAp/PDLLA scaffolds with 10% (m/m) HAp to PDLLA exhibited the highest cell adhesion and good cell proliferation capabilities and formed a well-organized cytoskeleton architecture after 7 days of culture. Hence, 3D HAp/PDLLA scaffolds as biomaterials showed potential for bone tissue applications.

Electroactive poly(vinylidene fluoride)-based structures for advanced applications.

Poly(vinylidene fluoride) (PVDF) and its copolymers are the polymers with the highest dielectric constants and electroactive responses, including piezoelectric, pyroelectric and ferroelectric effects. This semicrystalline polymer can crystallize in five different forms, each related to a different chain conformation. Of these different phases, the β phase is the one with the highest dipolar moment and the highest piezoelectric response; therefore, it is the most interesting for a diverse range of applications. Thus, a variety of processing methods have been developed to induce the formation of the polymer β phase. In addition, PVDF has the advantage of being easily processable, flexible and low-cost. In this protocol, we present a number of reproducible and effective methods to produce β-PVDF-based morphologies/structures in the form of dense films, porous films, 3D scaffolds, patterned structures, fibers and spheres. These structures can be fabricated by different processing techniques, including doctor blade, spin coating, printing technologies, non-solvent-induced phase separation (NIPS), temperature-induced phase separation (TIPS), solvent-casting particulate leaching, solvent-casting using a 3D nylon template, freeze extraction with a 3D poly(vinyl alcohol) (PVA) template, replica molding, and electrospinning or electrospray, with the fabrication method depending on the desired characteristics of the structure. The developed electroactive structures have shown potential to be used in a wide range of applications, including the formation of sensors and actuators, in biomedicine, for energy generation and storage, and as filtration membranes.

Microporous Polyurethane Thin Layer as a Promising Scaffold for Tissue Engineering.

The literature describes that the most efficient cell penetration takes place at 200–500 µm depth of the scaffold. Many different scaffold fabrication techniques were described to reach these guidelines. One such technique is solvent casting particulate leaching (SC/PL). The main advantage of this technique is its simplicity and cost efficiency, while its main disadvantage is the scaffold thickness, which is usually not less than 3000 µm. Thus, the scaffold thickness is usually far from the requirements for functional tissue reconstruction. In this paper, we report a successful fabrication of the microporous polyurethane thin layer (MPTL) of 1 mm thick, which was produced using SC/PL technique combined with phase separation (PS). The obtained MPTL was highly porous (82%), had pore size in the range of 65–426 µm and scaffold average pore size was equal to 154 ± 3 µm. Thus, it can be considered a suitable scaffold for tissue engineering purpose, according to the morphology criterion. Polyurethane (PUR) processing into MPTL scaffold caused significant decrease of contact angle from 78 ± 4° to 56 ± 6° and obtained MPTL had suitable hydrophilic characteristic for mammalian cells growth and tissue regeneration. Mechanical properties of MPTL were comparable to the properties of native tissues. As evidenced by biotechnological examination the MPTL were highly biocompatible with no observed apparent toxicity on mouse embryonic NIH 3T3 fibroblast cells. Performed studies indicated that obtained MPTL may be suitable scaffold candidate for soft TE purposes such as blood vessels.

A novel akermanite/poly (lactic-co-glycolic acid) porous composite scaffold fabricated via a solvent casting-particulate leaching method improved by solvent self-proliferating process.

Desirable scaffolds for tissue engineering should be biodegradable carriers to supply suitable microenvironments mimicked the extracellular matrices for desired cellular interactions and to provide supports for the formation of new tissues. In this work, a kind of slightly soluble bioactive ceramic akermanite (AKT) powders were aboratively selected and introduced in the PLGA matrix, a novel l-lactide modified AKT/poly (lactic-co-glycolic acid) (m-AKT/PLGA) composite scaffold was fabricated via a solvent casting-particulate leaching method improved by solvent self-proliferating process. The effects of m-AKT contents on properties of composite scaffolds and on MC3T3-E1 cellular behaviors in vitro have been primarily investigated. The fabricated scaffolds exhibited three-dimensional porous networks, in which homogenously distributed cavities in size of 300–400 μm were interconnected by some smaller holes in a size of 100–200 μm. Meanwhile, the mechanical structure of scaffolds was reinforced by the introduction of m-AKT. Moreover, alkaline ionic products released by m-AKT could neutralize the acidic degradation products of PLGA, and the apatite-mineralization ability of scaffolds could be largely improved. More valuably, significant promotions on adhesion, proliferation, and differentiation of MC3T3-E1 have been observed, which implied the calcium, magnesium and especially silidous ions released sustainably from composite scaffolds could regulate the behaviors of osteogenesis-related cells.

Enhancing bioactive properties of silk fibroin with diatom particles for bone tissue engineering applications.

Many studies have highlighted the role of silicon in human bone formation and maintenance. Silicon, in fact, is considered to nucleate the precipitation of hydroxyapatite and to reduce the bone resorption. For this reason, we have combined silk fibroin (SF) with silicon-releasing diatom particles (DPs), as potential material for bone tissue engineering applications. Sponges of fibroin loaded with different amounts and sizes of DPs were prepared by solvent casting-particulate leaching method, and their morphology, porosity and mechanical properties were evaluated. The biological effect of diatom addition was assessed on human osteosarcoma cell line MG63, a suitable osteoblast-like model, through cell adhesion, metabolic activity and proliferation assays. In addition, alkaline phosphatase activity, osterix and collagen type I production in MG63 cell line were assessed as markers of early bone formation to demonstrate a pro-mineralization potential of scaffolds. Results of the studies showed that addition to fibroin of diatoms particles improved the osteogenic properties of osteoblast-like cells compared with the pure SF. Copyright © 2016 John Wiley & Sons, Ltd.