Responses of microRNA in digestive glands of mussel Mytilus galloprovincialis exposed to polystyrene nanoplastics.

Polystyrene nanoplastics (PS-NPs) are typical accumulated nanoplastics in the marine environment and organisms, and have strong potential risks to marine ecological environment and human health. MiRNAs could respond to and participate in the response process of environmental stressors. However, the response of miRNAs to nanoplastics has not been fully explored. In this study, miRNA responses of digestive glands in mussels Mytilus galloprovincialis treated by 200 nm PS-NPs (20, 200, 2000 µg/L) for 7 days were characterized by BGISEQ-500 deep sequencing and bioinformatics analysis, along with histopathological quantification with planimetric parameters on hematoxylin and eosin (H&E) staining. Results showed that one novel miRNA (novel_mir63) and seven known miRNAs (miR-34_2, miR-34_5, miR-281_8, let-7-5p_6, miR-10, miR-124, miR-29b-3p) were significantly (adjusted P-value < 0.05) differentially expressed after PS-NPs treatments, and most of them were down-regulated expect for novel_mir63 and miR-34_2. Function analysis of target genes corresponding to these differentially expressed miRNAs indicated that PS-NPs disturbed the process related to metabolism, aging, cardiac function, neural excitation, and repairment. Among them, acetyl-CoA C-acetyltransferase and purine metabolism pathway played vital connection roles. Meanwhile, significantly morphology changes of digestive tubes obtained from H&E stained sections also implied severely disrupted metabolic capability in digestive glands, reflected by significantly increased mean diverticular radius (MDR) and mean luminal radius (MLR) values and the ratio of MLR to mean epithelial thickness (MET), and significantly decreased MET value and MET/MDR. Overall, these findings have revealed new characterization of miRNAs and their target genes in mussel M. galloprovincialis under PS-NPs stress, and provide important clues to further elucidate the toxicity mechanisms of PS-NPs.

Anti-Periodontitis Effects of Dendropanax morbiferus H.Lév Leaf Extract on Ligature-Induced Periodontitis in Rats.

Periodontitis is caused by pathogens in the oral cavity. It is a chronic infectious disease that causes symptoms including gingival bleeding and tooth loss resulting from the destruction of periodontal tissues coupled with inflammation. Dendropanax morbiferus H.Lév (DM) is a natural product that exhibits various biological activities with few side effects. In this study, the potential of DM leaf hot-water extracts (DMWE) as a treatment for periodontitis was determined and its anti-oxidant and anti-inflammatory effects were evaluated. Compounds in DMWE were identified by high-performance liquid chromatography (HPLC) and nitric oxide (NO) and prostaglandin E2 (PGE2) production was measured in RAW 264.7 cells. We measured the gingival index and gingival sulcus depth, and micro-CT was performed in vivo using a ligature-induced periodontitis rat model, which is similar to human periodontitis. The DMWE-treated group exhibited a decrease in cytokine concentration and relieved the gingival index and gingival sulcus depth compared with the periodontitis-induced control group. In addition, micro-CT and histological analysis revealed that DMWE exhibited anti-inflammatory effects and improved alveolar bone loss in periodontitis-induced rats. These findings suggest that DMWE has excellent anti-oxidant and anti-inflammatory effects that protect and prevent periodontal tissue damage and tooth loss caused by the inflammatory response.

Phasor-Fluorescence Lifetime Imaging Microscopy Analysis to Monitor Intercellular Drug Release from a pH-Sensitive Polymeric Nanocarrier.

The design of highly efficient drug carriers, and the development of appropriate techniques to monitor their mechanism of action and therapeutic effect, are both critical for improving chemotherapy. Herein, a polymeric nanoparticle, PAH-Cit/DOX (poly(allylamine)-citraconic anhydride/doxorubicin), was synthesized and used as a nanodrug system for the efficient delivery and pH-responsive release of doxorubicin (DOX) into cancer cells. The PAH-Cit/DOX nanoparticles were stable at physiological pH but effectively released DOX under weakly acidic conditions. The release efficiency was 90.6% after 60 h of dialysis in phosphate-buffered saline at pH 5.5. Confocal images showed the rapid movement of the drug from the cytoplasm to the nucleus, indicating the effective drug release MCF-7 cells. Notably, the combination of fluorescence lifetime imaging microscopy (FLIM) and phasor analysis (phasor-FLIM) provides an approach to monitor the dynamic change of DOX fluorescence lifetime in intercellular environments. Phasor-differentiated lifetime pixel intensity in FLIM images was quantified and used to evaluate the DOX release from nanocarriers, making it possible to detect the dynamics of intracellular release and transport of DOX.

Development and evaluation of a digital dental modeling method based on grating projection and reverse engineering software.

STATEMENT OF PROBLEM: For reasons of convenience and economy, attempts have been made to transform traditional dental gypsum casts into 3-dimensional (3D) digital casts. Different scanning devices have been developed to generate digital casts; however, each has its own limitations and disadvantages. PURPOSE: The purpose of this study was to develop an advanced method for the 3D reproduction of dental casts by using a high-speed grating projection system and noncontact reverse engineering (RE) software and to evaluate the accuracy of the method. MATERIAL AND METHODS: The methods consisted of 3 main steps: the scanning and acquisition of 3D dental cast data with a high-resolution grating projection system, the reconstruction and measurement of digital casts with RE software, and the evaluation of the accuracy of this method using 20 dental gypsum casts. The common anatomic landmarks were measured directly on the gypsum casts with a Vernier caliper and on the 3D digital casts with the Geomagic software measurement tool. Data were statistically assessed with the t test. RESULTS: The grating projection system had a rapid scanning speed, and smooth 3D dental casts were obtained. The mean differences between the gypsum and 3D measurements were approximately 0.05 mm, and no statistically significant differences were found between the 2 methods (P>.05), except for the measurements of the incisor tooth width and maxillary arch length. CONCLUSIONS: A method for the 3D reconstruction of dental casts was developed by using a grating projection system and RE software. The accuracy of the casts generated using the grating projection system was comparable with that of the gypsum casts.

Mandibular tori are associated with mechanical stress and mandibular shape.

PURPOSE: The influence of mechanical stimulation on the formation of torus mandibularis (TM) is still poorly understood. We sought to understand the etiology of TMs by investigating the role of parafunctional activity and mandibular morphology on the formation of TMs. MATERIALS AND METHODS: We designed a case-control study for patients attending the dental clinic of the present study (University of São Paulo School of Dentistry, São Paulo, SP, Brazil). Patients presenting with TMs were defined as cases, and those without TMs were defined as controls. Finite element analysis (FEA) was used in 3-dimensional mandibular models to examine the stress distribution in the mandibles with and without TMs. In addition, the associations of mandibular arch shape, mandibular cortical index, and parafunctional activity with the presence of T were assessed using odds ratio analysis. RESULTS: A total of 10 patients with TMs and 37 without TMs were selected (22 men and 25 women, mean age 54.3 ± 8.4 years). FEA showed a stress concentration in the region in which TMs form during simulation of parafunctional activity. The radiographic assessment showed that those with TMs were more likely to have a square-shaped mandible with sharp angles (P = .001) and a normal mandibular cortex (P = .03). The subjects without TMs had a round-shaped mandible with obtuse angles and an eroded mandibular cortex. CONCLUSIONS: Parafunctional activity could be causing the formation of TMs by concentrating mechanical stress in the region in which TMs usually form. Thus, mandibular geometries that favor stress concentration, such as square-shaped mandibles, will be associated with a greater prevalence of TMs.

Study on measurements for margin of safety in lateral operation of a transnasoethmoid-sphenoid approach to decompress the optic canal.

OBJECTIVE: The surgical approach through nasal and ethmoid cells to sphenoid sinus is a common clinical method to do the decompression of the optic canal. During this surgery, we can follow landmarks such as ethmoidal arteries. However, when we do the surgery, it is possible to open excessively in lateral operation and damage orbital medial wall. To prevent this from happening, we do a lot of measurements to estimate the distance in lateral operation. We hope to give surgeons some help in clinical use. METHODS: We chose 120 brain imaging findings that showed a normal appearance in our measuring area by means of three-dimensional reconstruction based on high-resolution spiral computed tomography scans. We chose several anatomic landmarks and measured the distances in lateral operation and located a projection point for directing this surgery. RESULTS: The mean values of distance from dacryon and the anterior foramen of the optic canal to the index plane were 5.439 ± 2.4496 and 9.334 ± 2.0628 mm. The mean values of distance from trisection points to the orbital medial wall were 7.359 ± 2.2262 and 6.911 ± 2.3102 mm. The mean value of distance from the projection point to the ipsilateral outer edge of the supraorbital notch was 30.379 ± 5.3676 mm. There are no significant differences for all the distance between the left side and right side. The median of right-side angle between the straight line connecting both sides of the outer edge of supraorbital notch and the straight line connecting the projection point with the ipsilateral outer edge of the supraorbital notch is larger than the left one and has a less variation than the left one. CONCLUSIONS: The lateral distance in surgical operation is consistent among individuals, which can give a safe area to surgeons in lateral operation. The location of the projection point gives surgeons an indication of direction to this surgery.

3D Poly (L-lactic acid) fibrous sponge with interconnected porous structure for bone tissue scaffold.

Large bone defects, often resulting from trauma and disease, present significant clinical challenges. Electrospun fibrous scaffolds closely resembling the morphology and structure of natural ECM are highly interested in bone tissue engineering. However, the traditional electrospun fibrous scaffold has some limitations, including lacking interconnected macropores and behaving as a 2D scaffold. To address these challenges, a sponge-like electrospun poly(L-lactic acid) (PLLA)/polycaprolactone (PCL) fibrous scaffold has been developed by an innovative and convenient method (i.e., electrospinning, homogenization, progen leaching and shaping). The resulting scaffold exhibited a highly porous structure (overall porosity = 85.9 %) with interconnected, regular macropores, mimicking the natural extracellular matrix. Moreover, the incorporation of bioactive glass (BG) particles improved the hydrophilicity (water contact angle = 79.7°) and biocompatibility and promoted osteoblast cell growth. In-vitro 10-day experiment revealed that the scaffolds led to high cell viability. The increment of the proliferation rates was 195.4 % at day 7 and 281.6 % at day 10. More importantly, Saos-2 cells could grow, proliferate, and infiltrate into the scaffold. Therefore, this 3D PLLA/PCL with BG sponge holds great promise for bone defect repair in tissue engineering applications.

Conducting biointerface of spider-net-like chitosan-adorned polyurethane/SPIONs@SrO2-fMWCNTs for bone tissue engineering and antibacterial efficacy.

In pursuit of enhancing bone cell proliferation, this study delves into the fabrication of porous scaffolds through the integration of nanomaterials. Specifically, we present the development of highly conductive chitosan (CS) nanonets on fibro-porous polyurethane (PU) bio-membranes. These nanofibers comprise functionalized multiwall carbon nanotubes (fMWCNTs), well-dispersed superparamagnetic iron oxide (SPIONs), and strontium oxide (SrO2) nanoparticles. The resulting porous scaffold exhibits remarkable interfacial biocompatibility, antibacterial properties, and load-bearing capability. Through meticulous in vitro investigations, the CS-PU/SPIONs/SrO2-fMWCNTs nanofibrous scaffolds have demonstrated a propensity to promote bone cell regeneration. Notably, the integration of these nanomaterials has been found to upregulate crucial bone-related markers, including ALP, ARS, COL-I, RUNX2, and SPP-I. The evaluation of these markers, conducted through quantitative real-time polymerase chain reaction (qRT-PCR) and immunocytochemistry, substantiates the improved cell survival and enhanced osteogenic differentiation facilitated by the integrated nanomaterials. This comprehensive analysis underscores the efficacy of CS-PU/SPIONs/SrO2-fMWCNTs bioscaffolds in promoting MC3T3-E1 cell regeneration within, thereby holding promise for advancements in bone tissue engineering and regenerative medicine.

Study on the determination of heavy metals in water samples with ultrasound-assisted dispersive liquid-liquid microextraction prior to FAAS.

A new, simple and rapid method based on dispersive liquid-liquid microextraction (DLLME) was developed for extracting and preconcentrating copper (Cu), nickel (Ni), lead (Pb) and cadmium (Cd) in water samples prior to flame atomic absorption spectrometry (FAAS) analysis. 1-(2-thiazolylazo)-naphthol (TAN) was used as chelating reagents, and non-ionic surfactant Triton X-114 and CCl(4) as disperser solvent and extraction solvent, respectively. Some influential factors relevant to DLLME, such as the concentration of TAN, type and volume of disperser and extraction solvent, pH and ultrasound time, were optimized. Under the optimal conditions, the calibration curve was linear in the range of 10-800 µg L(-1) for Cu and Ni, 10-500 µg L(-1) for Pb, and 10-1,000 µg L(-1) for Cd, respectively. The limits of detection for the four metal ions were below 0.5 µg L(-1), with the enhancement factors of 105, 66, 28 and 106 for Cu, Ni, Pb and Cd, respectively. The relative standard deviations (RSD, n = 6) were 2.6-4.1%. The proposed method was applied to determination of Cu, Ni, Pb and Cd in water samples and satisfactory relative recoveries (93.0-101.2%) were achieved.

FRET-Modulated Fluorescence Lifetime-Traceable Nanocarriers for Multidrug Release Monitoring and Synergistic Therapy.

In situ monitoring multidrug release in complex cellular microenvironments is significant, and currently, it is still a great challenge. In this work, a smart nanocarrier with the capability of codelivery of small molecules and gene materials as well as with Förster resonance energy transfer (FRET)-modulated fluorescence lifetime is fabricated by integrating gold nanoparticles (the acceptor) into dual-mesoporous silica loaded with multiple drugs (the donor). Once internalized into tumor cells, in weakly acidic environments, the conformation switch of the polymer grafted on nanocarriers causes its shedding from the mesopores, triggering the release of drugs. Simultaneously, based on the strong overlap between the emission spectrum of donors and the absorption spectrum of the acceptors, any slight fluctuation of the dissociation of the drugs from nanocarriers can result in a change in the FRET-modulated lifetime signal due to the extraordinarily sensitive FRET signal to the separation distance between donors and acceptors. All these implied the potential applications of this nanoplatform in various biomedical fields that require the codelivery and real-time monitoring of multidrug-based synergistic therapy.

Ultrasonic-assisted cloud point extraction for determination of nickel in water samples by flame atomic absorption spectrometry.

A novel method for the determination of nickel was established by ultrasonic-assisted cloud point extraction (UA-CPE) prior to flame atomic absorption spectrometry (FAAS) analysis. The nickel reacted with N,N'-bis(salicylidene)-1,2-ethanediamine (BSE) to form hydrophobic chelates, which were extracted into the micelles of alpha-[3,5-dimethyl-1-(2-methylpropyl)hexyl]-omega- poly(oxy-2-ethanediyl) (Tergitol TMN-6). Tergitol TMN-6 was used as green nonionic surfactant. BSE was synthesized and checked by nuclear magnetic resonance (NMR) spectra. The phase diagrams of the binary system, water-surfactant (Tergitol TMN-6), and the ternary systems, water-surfactant-salt, were determined. The effects of experimental conditions including pH of sample solution, concentration of chelating agent and surfactant, ultrasonic power, equilibration temperature and incubation time were evaluated in order to enhance sensitivity of the method. Under the optimal conditions, the calibration graph was linear in the range of 10-500 µg L(-1). The values obtained for the limit of detection and enrichment factor were 1.0 µg L(-1) and 30, respectively. The method was successfully applied to the analysis of nickel in water samples.

Adaptive Biosensing and Neuromorphic Classification Based on an Ambipolar Organic Mixed Ionic-Electronic Conductor.

Organic mixed ionic-electronic conductors (OMIECs) are central to bioelectronic applications such as biosensors, health-monitoring devices, and neural interfaces, and have facilitated efficient next-generation brain-inspired computing and biohybrid systems. Despite these examples, smart and adaptive circuits that can locally process and optimize biosignals have not yet been realized. Here, a tunable sensing circuit is shown that can locally modulate biologically relevant signals like electromyograms (EMGs) and electrocardiograms (ECGs), that is based on a complementary logic inverter combined with a neuromorphic memory element, and that is constructed from a single polymer mixed conductor. It is demonstrated that a small neuromorphic array based on this material effects high classification accuracy in heartbeat anomaly detection. This high-performance material allows for straightforward monolithic integration, which reduces fabrication complexity while also achieving high on/off ratios with excellent ambient p- and n-type stability in transistor performance. This material opens a route toward simple and straightforward fabrication and integration of more sophisticated adaptive circuits for future smart bioelectronics.

Revisable and high-strength wheel-spun alginate/graphene oxide based fibrous rods towards a flexible and biodegradable rib internal fixation system.

The intramedullary splint insertion fixation system is the mainstream clinical solution to severe rib fractures. However, the titanium alloy scaffolds have limitations in biocompatibility, flexibility and complexity of surgeries. Here we present a revisable wheel-spun alginate (Alg)/graphene oxide (GO)-based fibrous rod as a potential alternative for a rib internal fixation system. The reversible fusion and fission capability was obtained by optimized Alg/GO blended spinning and GO coating post-treatment. The mechanical performance of the demonstrated rod samples matches the properties of the human rib. A self-designed cubic matrix was used to conduct in situ cell culture. In vitro evaluation not only confirms the cell viability and migration on the fibers' surface, but also investigated the degradation and fission performance of fibrous rods. With a simple, minimally invasive implantation and controlled swelling, Alg/GO fibrous rods are able to tightly fix the rib fracture wound while maintaining sufficient flexibility.

Delivery of CRISPR/Cas9 Plasmid DNA by Hyperbranched Polymeric Nanoparticles Enables Efficient Gene Editing.

Gene editing nucleases such as CRISPR/Cas9 have enabled efficient and precise gene editing in vitro and hold promise of eventually achieving in vivo gene editing based therapy. However, a major challenge for their use is the lack of a safe and effective virus-free system to deliver gene editing nuclease elements. Polymers are a promising class of delivery vehicle due to their higher safety compared to currently used viral vectors, but polymers suffer from lower transfection efficiency. Polymeric vectors have been used for small nucleotide delivery but have yet to be used successfully with plasmid DNA (pDNA), which is often several hundred times larger than small nucleotides, presenting an engineering challenge. To address this, we extended our previously reported hyperbranched polymer (HP) delivery system for pDNA delivery by synthesizing several variants of HPs: HP-800, HP-1.8K, HP-10K, HP-25K. We demonstrate that all HPs have low toxicity in various cultured cells, with HP-25K being the most efficient at packaging and delivering pDNA. Importantly, HP-25K mediated delivery of CRISPR/Cas9 pDNA resulted in higher gene-editing rates than all other HPs and Lipofectamine at several clinically significant loci in different cell types. Consistently, HP-25K also led to more robust base editing when delivering the CRISPR base editor "BE4-max" pDNA to cells compared with Lipofectamine. The present work demonstrates that HP nanoparticles represent a promising class of vehicle for the non-viral delivery of pDNA towards the clinical application of gene-editing therapy.

Stretchable colour-sensitive quantum dot nanocomposites for shape-tunable multiplexed phototransistor arrays.

High-performance photodetecting materials with intrinsic stretchability and colour sensitivity are key requirements for the development of shape-tunable phototransistor arrays. Another challenge is the proper compensation of optical aberrations and noises generated by mechanical deformation and fatigue accumulation in a shape-tunable phototransistor array. Here we report rational material design and device fabrication strategies for an intrinsically stretchable, multispectral and multiplexed 5 × 5 × 3 phototransistor array. Specifically, a unique spatial distribution of size-tuned quantum dots, blended in a semiconducting polymer within an elastomeric matrix, was formed owing to surface energy mismatch, leading to highly efficient charge transfer. Such intrinsically stretchable quantum-dot-based semiconducting nanocomposites enable the shape-tunable and colour-sensitive capabilities of the phototransistor array. We use a deep neural network algorithm for compensating optical aberrations and noises, which aids the precise detection of specific colour patterns (for example, red, green and blue patterns) both under its flat state and hemispherically curved state (radius of curvature of 18.4 mm).

A mutant of Asia 1 serotype of Foot-and-mouth disease virus with the deletion of an important antigenic epitope in the 3A protein.

Foot-and-mouth disease is a highly contagious viral disease of cloven-hoofed animals. The availability of a vaccine for differentiating infected from vaccinated animals (DIVA) is crucial for the control and eradication of Foot-and-mouth disease virus (FMDV). Because traditional inactivated vaccines may contain trace nonstructural proteins interfering with the DIVA, we hypothesized that mutant FMDV with deletion of immunodominant epitopes may be valuable. Our previous study has generated a full-length cDNA clone (pBSAs) of FMDV serotype Asia 1 isolated in China. In this study, a B-cell epitope was identified in the 3A region of a nonstructural protein (NSP) by anti-FMDV cattle sera. Furthermore, we generated recombinant FMDV (rvAs-3A14D) by selectively deleting 14 amino acids (position 91-104) in the 3A region of the NSP. Following in vitro transcription and transfection in BHK-21 cells, we successfully rescued the rvAs-3A14D from BHK-21 cells. Characterization of the rvAs-3A14D revealed that the infectivity, antigenicity, and replication kinetics in BHK-21 cells and virulence in mice of the rvAs-3A14D were similar to that of its parent virus. Notably, the mutant rvAs-3A14D only replicated well in BHK-21 but did poorly in primary calf kidney cells. These data suggest that the recombinant FMDV with deletion of this epitope in the NSP may be potentially used as a candidate inactivated vaccine. Therefore, the application of the marker vaccine and differential diagnostic tests may open a promising new avenue for the development of a vaccine for DIVA.

Hierarchical Porous Recycled PET Nanofibers for High-Efficiency Aerosols and Virus Capturing.

Plastic crisis, especially for poly(ethylene terephthalate) (PET) bottles, has been one of the greatest challenges for the earth and human beings. Processing recycled PET (rPET) into functional materials has the dual significance of both sustainable development and economy. Providing more possibilities for the engineered application of rPET, porous PET fibers can further enhance the high specific surface area of electrospun membranes. Here, we use a two-step strategy of electrospinning and postprocessing to successfully control the surface morphology of rPET fibers. Through a series of optical and thermal characterizations, the porous morphology formation mechanism and crystallinity induced by solvents of rPET fibers were discussed. Then, this work further investigated both PM2.5 air pollutants and protein filtration performance of rPET fibrous membrane. The high capture capability of rPET membrane demonstrated its potential application as an integrated high-efficiency aerosol filtering solution.

Analytical model of I-bar clasps for removable partial dentures.

OBJECTIVE: Clasps of removable partial dentures (RPDs) often suffer from fatigue stress that leads to plastic deformation, loss of retention, and RPD failure. Recently, computer-based technologies were proposed to optimize clasp geometry design. The objective of this study was to create an analytic model of I-bar clasps for computer-aided design (CAD)-RPD. METHODS: The analytical model based on mechanical laws was established to simulate I-bar clasp retention, and optimize its design. The model considered the lengths of the vertical (L1) and horizontal (L2) arms of the I-bar as well as the radius (r) of its half-round cross-section. The analytical model was validated with mechanical experiments evaluating the retention of cobalt-chromium (Co-Cr) clasps in vitro and compared with finite element analysis (FEA). RESULTS: The analytical model was in good agreement with the mechanical experiments and FEA, and showed that I-bar clasp design could provide optimal mechanical performance as long as the length of arms (L1 and L2) do not exceed 6 mm. Clasps with L1 > 8 mm and L2 > 9 mm presented stress values exceeding the fatigue limit of Co-Cr. The proposed solution was to increase the radius of I-bar to conserve the initial mechanical performance of Co-Cr. SIGNIFICANCE: Co-Cr I-bar clasps perform best on teeth with reduced mesiodistal dimensions (canine and premolar), and their designs could be optimized to prevent stress from reaching the yield strength and the fatigue failure limit.

High strength and strain alginate fibers by a novel wheel spinning technique for knitting stretchable and biocompatible wound-care materials.

Alginate fibrous materials have been applied as wound dressing to enhance wound healing due to its nontoxic, biodegradable, and hemostatic nature. Conventional nonwoven fabrication tactics, however, showed weakness in inflammation, degradation stability and mechanical properties. Herein, the wet-spun alginate fibers were prepared by a novel wheel spinning technique, then knitted into wound dressing. Benefiting from optimized wet spinning parameters and the agglomeration of alginate multimers, the fibers were endowed with elevated mechanical performances and biodegradability, which allowed for the feasibility of knitting wound-care materials. Using the new wheel spinning technique, high strength alginate fibers with 173 MPa were produced with breaking strain up to 18% and toughness of 16.16 MJ*m-3. Meanwhile, alginate fibers with high breaking strain reaching 35% were produced with tensile strength of 135 MPa and toughness of 37.47 MJ*m-3. The overall mechanical performances of these alginate fibers with high breaking strain are significantly higher (up to 2 times) than those published in the literature in term of toughness. In vitro degradation evaluation revealed that this wet spun fibrous dressing had good aqueous absorbency (50%) and sustained biodegradation properties. Furthermore, the consequent cell viability study also proved that this alginate knitted fabric is biocompatible for being applied as wound dressing.

Hierarchical porous silk fibroin/poly(L-lactic acid) fibrous membranes towards vascular scaffolds.

Fibrous membranes played an important role to prepare tubular scaffolds for muscular artery regeneration. In this study, a strategy has been developed to combine silk fibroin (SF) with highly porous electrospun poly(L-lactic acid) (PLLA) fibrous membrane towards vascular scaffolds. After PLLA fibres were electrospun and collected, they were immersed into acetone to generate a porous structure with ultra-high surface area. While the pores on PLLA fibres were fulfilled with SF solution and dried, SF was coated uniformly and tightly on PLLA fibres. A multi-layer tubular structure of the tunica media was simulated by winding and stacking a strip of electrospun fibrous membrane. In vitro viability and morphology studies of A7r5 smooth muscle cells were undertaken for up to 14 days. Because the hydrophilicity of SF/PLLA composite fibres were improved dramatically, it had a positive effect on cell adhesion rate (97%) and proliferation (64.4%). Moreover, good cell morphology was observed via a multiphoton laser confocal microscope on SF/PLLA bioactive materials. These results demonstrated that the hierarchical porous SF/PLLA fibrous membranes are promising off-the-shelf scaffolds for muscular artery regeneration.