Cytocompatibility and Osteogenesis of Adipose Tissue-Derived Stem Cells on POSS-PEG Coated Collagen.

Nanostructured POSS-PEG nanoparticles (NPs, 42.4 nm ~) synthesized by formation of the urethane linkage between the monoisocyanate group (O═C═N-) of Polyhedral oligosilsesquioxane (POSS) macromers and the diol end groups (-OH) of polyethylene glycol (PEG) homopolymers as catalyzed by dibutyl tin dilaurate are of great interest for biomedical applications. However, NP materials based on nonorganic compounds can be cytotoxic. In this study, the preparation of PEG-POSS NPs followed the coating collagen assembly, which alleviates this problem. They also showed controlled surface properties in such a manner that hydrophobicity and biocompatibility were both reachable to give rise to improved cell viability. It indicates that the PEG-POSS coated collagen was appropriate for the proliferation of adipose tissue-derived stem cells to osteogenesis.

Osteoblastic cells culture on electrospun poly(ε-caprolacton) scaffolds incorporating amphiphilic PEG-POSS telechelic.

In this work, novel poly(ε-caprolactone) (PCL) fibrous membranes incorporating amphiphilic polyhedral oligosilsesquioxane (POSS) telechelic (PEG-POSS telechelic) were prepared via electrospinning. The unique microstructure, morphology, thermal stability of the resulting PCL/PEG-POSS telechelic electrospun nanowebs were investigated by X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis, respectively. The addition of amphiphilic PEG-POSS telechelic strongly influenced the fiber diameters, microstructures of the resultant PCL/PEG-POSS telechelic nanofibers, compared to pure PCL nanofibers. The potential biomedical applications of such PEG-POSS telechelic nanowebs as a scaffolding material were also evaluated in vitro using mouse osteoblast-like MC3T3-E1 cells. The cell adhesion, spreading, and interaction behavior of pure PCL and PCL/PEG-POSS telechelic fibrous membranes were explored. It was found that electrospun PCL fibrous membranes incorporating amphiphilic PEG-POSS telechelic showed higher initial cell attachment than pure PCL due to the higher surface free energy of POSS siloxanes. Moreover, the obtained PCL/PEG-POSS telechelic fibrous scaffolds were found to be nontoxic and to maintain the good adhesion ratio between cells and surface (about ~93 %) after cell culturing for 24 h.

In Vitro and Anti-Inflammatory Activity Evaluation Nanofibers from a Breath Mask and Filter Based on Polyurethane and Polyvinylidene Fluoride.

Nanofiber (NF) products exhibit outstanding performances in materials science, textiles, and medicine that cannot be realized using conventional technologies. However, the safety of such products is debated because of the potential health risks that nanomaterials pose and the lack of standardized guidelines for the safety evaluation of NF products. The global safety evaluations of nanomaterials have focused on evaluating the cytotoxicity of low-dimensional materials, including nanoparticles and nanotubes, based on OECD (Organization for Economic Co-operation and Development) criteria. NFs are one-dimensional materials with nanometer diameters and considerable lengths. Many fibers are applied in a densely woven web-like form, so assessing cellular penetration and fiber toxicity using the same methods is inappropriate. This study verifies the safety of the polyurethane (PU) and polyvinylidene fluoride (PVDF) polymers currently applied in filters and masks. To this end, polymer NFs were collected from each product, and the NFs were compared with reference samples using FT-IR and Raman spectroscopy. For the safety evaluation, DMSO stocks of varying concentrations of PVDF and PU NFs (at 0.5, 1, 5, and 10 µg/mL) were prepared. The cytotoxicity and inhibitory effects on nitric oxide production and protein expression obtained via Western blot were identified.

Effect of Cross-Linker Length on the Absorption Characteristics of the Sodium Salt of Cross-Linked Polyaspartic Acid.

For the development of biodegradable superabsorbent polymers, the effect of the cross-linking length on the absorption characteristics of the Na salt of polyaspartic acid (PAspNa) was demonstrated using different concentrations of diamine cross-linking agents bearing carbon chains of different lengths, viz., ethylenediamine, 1,6-hexamethylenediamine, 1,8-diaminooctane, 1,10-diaminodecane, and 1,12-diaminododecane were used as cross-linking agents. The absorption of PAspNa was measured in deionised water and in a 0.9% aqueous NaCl solution. Under the conditions tested, when the alkyl chain of PAspNa was too short or too long, the absorbency was low and the cross-linking length was optimum. The success of the cross-linking reaction was confirmed by FT-IR spectroscopy. The degree of cross-linking was estimated and the ideal concentration for maximum water absorption was determined by elemental analysis. The sample obtained by cross-linking 1,8-diaminooctane at a concentration of 0.11 g/g polysuccinimide (PSI) showed the highest absorption. The thermal properties of each material were determined by dynamic scanning calorimetry. Therefore, the length of the cross-linking agent was found to strongly influence water absorption.

Targeted drug release system based on pH-responsive PAA-POSS nanoparticles.

An amphipathic PAA-POSS@DOX drug delivery system that responds sensitively to pH changes in the cancer microenvironment has been developed using a nanoparticle based on inorganic polyhedral oligomeric silsesquioxane (POSS). POSS was introduced to the carboxylic acid group of polyacrylic acid to which doxorubicin anticancer drug was loaded to prepare 480 ± 192 nm self-assembled nanoparticles. PAA-POSS had a high loading efficiency of over 75% and doxorubicin was quickly released to the target area responding sensitively to weakly acidic conditions. The possibility of employing PAA-POSS as a targeted drug delivery system has been confirmed by observing the death of cells of the MDA-MB-231 breast cancer line.

Novel cancer stem cell marker MVP enhances temozolomide-resistance in glioblastoma.

The resistance of highly aggressive glioblastoma multiforme (GBM) to chemotherapy is a major clinical problem resulting in a poor prognosis. GBM contains a rare population of self-renewing cancer stem cells (CSCs) that proliferate, spurring the growth of new tumors, and evade chemotherapy. In cancer, major vault protein (MVP) is thought to contribute to drug resistance. However, the role of MVP as CSCs marker remains unknown and whether MVP could sensitize GBM cells to Temozolomide (TMZ) also is unclear. We found that sensitivity to TMZ was suppressed by significantly increasing the MVP expression in GBM cells with TMZ resistance. Also, MVP was associated with the expression of other multidrug-resistant proteins in tumorsphere of TMZ-resistant GBM cell, and was highly co-expressed with CSC markers in tumorsphere culture. On the other hands, knockdown of MVP resulted in reduced sphere formation and invasive capacity. Moreover, high expression of MVP was associated with tumor malignancy and survival rate in glioblastoma patients. Our study describes that MVP is a potentially novel maker for glioblastoma stem cells and may be useful as a target for preventing TMZ resistance in GBM patients.

Insulin smart drug delivery nanoparticles of aminophenylboronic acid-POSS molecule at neutral pH.

Self-regulated "smart" insulin administration system that mimic pancreatic endocrine function would be highly desirable for diabetes management. Here, a glucose-responsive continuous insulin delivery system is developed, where novel polyhedral oligosilsesquioxane (POSS) modified with 3-aminophenylboronic acid (APBA) were used to encapsulate insulin (insulin entrapment efficiency: 73.2%) to prepare a fast response, high stability, good distribution, and excellent biocompatible system. Due to the strong hydrophobicity of POSS, the POSS moiety is located at the core in aqueous solution and combines with the boronic group of APBA and the diol generated in PEG-insulin to form a nanomicelle structure, that is, nanoparticles naturally. Micelles self-assembled from these molecules possess glucose-responsiveness at varying glucose concentrations. The interaction of the PBA and diol containing insulin via boronate ester bond and its interchange with glucose was investigated by FT-IR, 1H NMR and XPS. Furthermore, the successful glucose-triggered release of insulin from the POSS-APBA micelles was investigated at neutral pH. A linear graph was plotted with the measured released insulin vs glucose concentrations, with a linear correlation coefficient (R2) value close to 1. Circular dichroism (CD) spectroscopy analysis was performed to measure insulin activity by comparing secondary structures of insulin, PEG-Insulin, and POSS-APBA@insulin. When confirming intracellular apoptosis signaling, cleaved caspase 3 and caspase 9 were not increased by 640 µg/ml POSS-APBA and POSS-APBA@insulin in HeLa, HDF and HUVE cells. Application in the biomedical field for controlled delivery of insulin appear to be promising.

Wet-spun bi-component alginate based hydrogel fibers: Development and in-vitro evaluation as a potential moist wound care dressing.

In this study, bi-component alginate-hyaluronic acid (AHA) fibers were developed by using two different routes. In the first method, sodium alginate dope solution was extruded into a coagulation bath containing CaCl2 and subsequently dip-coated with hyaluronic acid (HA) whereas, in the second method, hyaluronic acid-containing sodium alginate dope solution was directly extruded into CaCl2 bath. The resulting AHA fibers were then dehydrated in 25-100% v/v acetone solutions and dried in air. The fibers were characterized by surface morphology, physicochemical analysis, mechanical performance, swelling percentage, and total liquid absorption (g/g), cell viability, and release behavior. The results showed that AHA fibers produced by the second method have better mechanical performance, high liquid absorption, and swelling percentage with a more controlled release of hyaluronic acid. The AHA fibers showed high biocompatibility toward nHDF cell line in in-vitro testing, and the MVTR values (650-800 g/m2/day) are in a suitable range for maintaining a moist wound surface proving to be appropriate for promoting wound healing.

Novel glucose-responsive of the transparent nanofiber hydrogel patches as a wearable biosensor via electrospinning.

Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions. However, the high crystallinity of NFs limits the achievement of transparency via electrospinning. Transparent poly(vinyl alcohol)/ß-cyclodextrin polymer NF hydrogels contacted with reverse iontophoresis electrodes were prepared for the development of a non-invasive continuous monitoring biosensor platform of interstitial fluid glucose levels reaching ~ 1 mM. We designed the PVA/BTCA/ß-CD/GOx/AuNPs NF hydrogels, which exhibit flexibility, biocompatibility, excellent absorptivity (DI water: 21.9 ± 1.9, PBS: 41.91 ± 3.4), good mechanical properties (dried: 12.1 MPa, wetted: 5.33 MPa), and high enzyme activity of 76.3%. Owing to the unique features of PVA/ß-CD/GOx containing AuNPs NF hydrogels, such as high permeability to bio-substrates and rapid electron transfer, our biosensors demonstrate excellent sensing performance with a wide linear range, high sensitivity(47.2 µA mM-1), low sensing limit (0.01 mM), and rapid response time (< 15 s). The results indicate that the PVA/BTCA/ß-CD/GOx/AuNPs NF hydrogel patch sensor can measure the glucose concentration in human serum and holds massive potential for future clinical applications.

A cellulose/ß-cyclodextrin nanofiber patch as a wearable epidermal glucose sensor.

In this study, we aimed to develop a cellulose/ß-cyclodextrin (ß-CD) electrospun immobilized GOx enzyme patch with reverse iontophoresis for noninvasive monitoring of interstitial fluid (ISF) glucose levels (0.1-0.6 mM dm-3). In vitro analysis, performed using a sensor attached to flexible substrates, revealed that the high diffusion coefficient (9.0 × 10-5 cm2 s-1), the linear correlation coefficient (R 2 = 0.998), the detection limit (9.35 × 10-5 M), and the linear range sensitivity (0-1 mM) of the sensor (5.08 µA mM-1) remained unaffected by the presence of interfering substances (e.g., fructose, sucrose, uric acid, and acetaminophen) at physiological levels. The present results indicate that the new epidermal sensing strategy using nanofibers for continuous glucose monitoring has potential to be applied in diagnosis of diabetes.

d-Glucose recognition based on phenylboronic acid-functionalized polyoligomeric silsesquioxane fluorescent probe.

We report a new strategy to synthesize hybrid fluorescent nanosensors consisting of phenylboronic acid-functionalized POSS (POSS-PBA) and diol-modified 8-anilino-1-naphthalenesulfonic acid (ANSA (a fluorescent dye)) for the detection of the biologically important d-glucose. The probe was characterized by FT-IR and 1H NMR analyses, and the photoluminescence intensity was measured under various conditions to confirm its glucose sensing ability. Our POSS-APBA-dye probe could detect glucose at concentrations of 0-20 mg/mL, with a good linear relationship even at low glucose concentrations of 0-1 mg/mL. The properties of the POSS-APBA-dye probe were evaluated and compared with those of an APBA-dye probe. The glucose sensing ability of our POSS-APBA-dye probe was largely unaffected by the presence of interfering substances. The probe showed high sensing ability in a pH 5 environment and long-term (approximately 40 days) fluorescence stability.

Design and characterization of dual drug delivery based on in-situ assembled PVA/PAN core-shell nanofibers for wound dressing application.

Core-shell nanofibers with the ability to carry multiple drugs are attracting the attention to develop appropriate drug delivery systems for wounds dressing applications. In this study, biocompatible core-shell nanofibers have been designed as a promising dual-drug carrier with the capability of delivering both water-soluble and organic solvent-soluble drugs simultaneously. With the aim of fabricating the core-shell nanofibers, the dipping method has been employed. For this propose, core nanofibers made from polyvinyl alcohol (PVA) were immersed in various concentrations of polyacrylonitrile (PAN) and cross-linked by dipping into ethanol. Diclofenac sodium salt (DSs) and gentamicin sulfate (GENs) have been loaded into the core and shell nanofibers as models of the drug, respectively. The morphology study of core-shell nanofibers showed that the concentrations between 1% w/w up to 2% w/w PAN/GENs, with deep penetration into the internal layers of PAV/DSs nanofibers could lead to the core-shell structure. The cytotoxicity results showed the competency of designed core-shell nanofibers for wound dressing application. Also, the release profile exhibits the controllable behavior of drug release.

Wound healing properties of a 3-D scaffold comprising soluble silkworm gland hydrolysate and human collagen.

Biomaterials that serve as scaffolds for cell proliferation and differentiation are increasingly being used in wound repair. In this study, the potential regenerative properties of a 3-D scaffold containing soluble silkworm gland hydrolysate (SSGH) and human collagen were evaluated. The scaffold was generated by solid-liquid phase separation and a freeze-drying method using a homogeneous aqueous solution. The porosity, swelling behavior, protein release, cytotoxicity, and antioxidative properties of scaffolds containing various ratios of SSGH and collagen were evaluated. SSGH/collagen scaffolds had a high porosity of 61-81% and swelling behavior studies demonstrated a 50-75% increase in swelling, along with complete protein release in the presence of phosphate-buffered saline. Cytocompatibility of the SSGH/collagen scaffold was demonstrated using mesenchymal stem cells from human umbilical cord. Furthermore, SSGH/collagen efficiently attenuated oxidative stress-induced cell damage. In an in vivo mouse model of wound healing, the SSGH/collagen scaffold accelerated wound re-epithelialization over a 15-day period. Overall, the microporous SSGH/collagen 3-D scaffold maintained optimal hydration of the exposed tissues and decreased wound healing time. These results contribute to the generation of advanced wound healing materials and may have future therapeutic implications.

Fabrication of nano-hydroxyapatite on electrospun silk fibroin nanofiber and their effects in osteoblastic behavior.

In this study, a novel tissue engineering scaffold material of electrospun silk fibroin/nano-hydroxyapatite (nHA) biocomposite was prepared by means of an effective calcium and phosphate (Ca-P) alternate soaking method. nHA was successfully produced on regenerated silk fibroin nanofiber as a substrate within several minutes without any pretreatments. The morphologies of both nonmineralized and mineralized nanofibers were analyzed using a field-emission scanning electron microscopy (FESEM). The crystallographic phases of the nHA were analyzed using X-ray diffraction (XRD). Fourier transform infrared (FTIR) spectrophotometer and thermogravimetry analyses (TGA) were employed to determine the type of functional groups and the amount of nHA presenting in the silk/nHA biocomposite nanofibers, respectively. The osteoblastic activities of this novel nanofibrous biocomposite scaffold were also investigated by employing osteoblastic-like MC3T3-E1 cell line. The cell functionality such as alkaline phosphatase (ALP) activity was ameliorated on mineralized nanofibers. All these results indicated that this silk/nHA biocomposite scaffold material may be a promising biomaterial for bone tissue engineering.