Fabrication of a Micro/Nano-Net Membrane Using Cellulose Nanocrystals Derived from Seaweed.

We have successfully extracted cellulose nanocrystals (CNCs) from seaweed by removing unwanted materials via our modified process. The prepared CNCs were mixed with two biocompatible polymers (polyethylene oxide (PEO)/Eudragit S100). We used the most popular electrospinning method to fabricate a micro/nano-net membrane. The formation of nano-webs between fundamental micro/nanofibers was observed via SEM and TEM, according to the mixing ratio of the solution (PEO:Eudragit: 1:1, 2:1, 3:1 wt:wt%) with 0, 5, 10% CNCs per polymer weight. We found the optimal condition to fabricate nano-net in the membrane and expect it to be applicable for wound healing, tissue engineering, and various filter applications.

Development of Nanofiber Reinforced Double Layered Cabin Air Filter Using Novel Upward Mass Production Electrospinning Set Up.

Recently, numerous researchers are interested in the development of new air filter because of air pollution caused by rapid industrialization and urbanization. The major concerns in developing air filters are: pressure drop and filtration efficiency which are considered significant. As the pressure drop increases, the energy consumption becomes high. In this study, we developed a novel air filter (polyurethane fiber mat) for nano size filtration using a mass production electrospinning, which is expected to enhance filtration efficiency and pressure drop effects. To determine the optimal electrospinning conditions for filter efficiency, various concentrations (8, 10, 12 wt/wt%) of thermoplastic polyurethane were prepared and employed. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) were used for fiber characterization, and finally, efficiency test was conducted to evaluate the filter performance of developed nanofiber-based air filter. From this study, it could be concluded that optimization by adjusting the polymer concentration and electrospinning operating condition was the best efficient alternative method to fabricate nano-fibrous air filter system with improved filtration performance.

Electrochemical technique to develop surface-controlled polyaniline nano-tulips (PANINTs) on PCL-reinforced chitosan functionalized (CS-f-Fe2O3) scaffolds for stimulating osteoporotic bone regeneration.

Bone defects pose significant challenges in orthopedic surgery, often leading to suboptimal outcomes and complications. Addressing these challenges, we employed a three-electrode electrochemical system to fabricate surface-controlled polyaniline nano-tulips (PANINTs) decorated polycaprolactone (PCL) reinforced chitosan functionalized iron oxide nanoparticles (CS-f-Fe2O3) scaffolds. These structures were designed to emulate the natural extracellular matrix (ECM) and promote enhanced osseointegration by establishing a continuous interface between host bone and graft, thereby improving both biological processes and mechanical stability. In vitro experiments demonstrated that PANINTs-PCL/CS-f-Fe2O3 substrates significantly promoted the proliferation, differentiation, and spontaneous outgrowth and extension of MC3T3-E1 cell activity. The nanomaterials exhibited increased cell viability and osteogenic differentiation, as evidenced by elevated expression of bone-related markers such as ALP, ARS, COL-I, RUNX2, and SPP-I, as determined by qRT-PCR. Our findings underscore the regenerative potential of in situ cell culture systems for bone defects, emphasizing the targeted stimulation of essential cell subpopulations to facilitate rapid bone tissue regeneration.

In-situ cellulose-framework templates mediated monodispersed silver nanoparticles via facile UV-light photocatalytic activity for anti-microbial functionalization.

Cellulose is well known as a biocompatible material or natural reducing material. In this study, As an eco-friendly and facile method, we prepared monodispersed silver nanoparticles (AgNPs) in cellulose-framework through photocatalytic reaction. and we fabricated electrospun fiber scaffolds with excellent antibacterial properties and biocompatibility. UV-irradiation causes the electrical change of the cellulose-framework, thereby converting Ag ions into Ag particles. We applied a three-electrode system to confirm the phenomenon. Through STEM and EDS, it was found that the synthesized AgNPs were monodisperse in the nanofibers, and antibacterial activity was confirmed using gram-negative and gram-positive bacteria. In addition, it was suggested that the gradual release of simvastatin contained in the nanofibers and excellent mineralization would be easy to apply to bone regeneration. Therefore, the manufactured composite electrospun fiber mat can be used not only in biomedical fields but also in various applications that need to prevent the accumulation of microorganisms.

Engineered cellular microenvironments from functionalized multiwalled carbon nanotubes integrating Zein/Chitosan @Polyurethane for bone cell regeneration.

A biomimetic-based approaches, especially with artificial scaffolding, have established great potential to provide tissue regeneration capacity and an effective way to bridge the gap between host cell responses and organ demands. However, the synthesis of biomaterial is most efficient when the functional behavior involved most resembles the natural extracellular matrix. Here, a fibrous scaffold was engineered by integrating zein and chitosan (CS) in to polyurethane (PU) associated with functionalized multiwalled carbon nanotubes (fMWCNTs) as a bone cell repair material. The chitosan-based, tissue-engineered scaffold containing 0.1 mg/mL fMWCNTs shows potent synergistic results where improved biomechanical strength, hydrophilicity and antibacterial efficacy produce a scaffold akin to a truly natural extracellular matrix found in the bone cell microenvironments. The scaffold enables rapid cell-to-cell communication through a bio-interface and greatly promotes the regenerative effect of pre-osteoblast (MC3T3-E1) which is reflected in terms of cell growth, proliferation, and differentiation in our in vitro experiments. Alizarin red staining analysis, alkaline phosphatase activity, and Western blotting also confirm the nucleation of hydroxyapatite (HA) nanocrystals and the expression of osteogenic protein markers, all of which indicate the scaffold's excellent osteoinductive properties. These results suggest that this precisely engineered PU/Zein/CS-fMWCNTs fibrous scaffold possesses suitable biological behavior to act as an artificial bone extracellular matrix that will ensure bone cell regeneration while contributing numerous benefits to the field of artificial bone grafts.

Fabrication of Antibacterial Nanofibrous Membrane Infused with Essential Oil Extracted from Tea Tree for Packaging Applications.

Nanofibers made by electrospinning are being applied to an unlimited number of applications. In this paper, we propose the fabrication of antimicrobial functional nanofibers infused with essential oil for packaging applications that can extend the shelf-life of fruits. The morphology of nanofibers with different concentrations of essential oil was characterized by SEM and mechanical enhancement was confirmed via universal testing machine (UTM). The surface chemistry and crystalline of the nanofibers were investigated by FTIR and XRD, respectively. The CO2 reduction study was carried out using a hand-made experimental apparatus and nanofiber hydrophobicity, which can prevent moisture penetration from the outside, was evaluated by contact angle. Antimicrobial properties of the functional nanofibers were estimated by using Gram-negative/positive bacteria. The cytotoxicity of the functional nanofibers was studied using fibroblast cells. Furthermore, this study investigated how long the shelf-life of tomatoes was extended. The nanofibers could serve as a multifunctional packaging, as an emerging technology in agricultural products, and even contribute to a better quality of various distributed agricultural products.

Polydopamine-based Implantable Multifunctional Nanocarpet for Highly Efficient Photothermal-chemo Therapy.

We report a design and fabricate multifunctional localized platform for cancer therapy. Multiple stimuli-responsive polydopamine (PDA) was used for surface modification of electrospun doxorubicin hydrochloride (DOX) loaded polycaprolactone (PCL) fibers to make a designated platform. Photothermal properties such as photothermal performance and stability of the resulting composite mats were studied under the irradiation of the near-infrared (NIR) laser of 808 nm. With the incorporation of PDA into the fiber, a remarkable increase of local temperature was recorded under NIR illumination in a concentration-dependent manner with excellent stability. Drug released assay results revealed PDA coated PCL-DOX mats showed pH and NIR dual responsive behavior thereby exhibiting improved drug release in an acidic medium compared to physiological pH condition (pH 7.4) which is further increased by NIR exposure. The cancer activity in vitro of the mats was evaluated using cell counting (CCK) and live and dead cell assays. The combined effect of NIR mediated hyperthermia and chemo release resulting improved cells death has been reported. In summary, this study presents a major step forward towards a therapeutic model to cancer treatment utilizing pH and NIR dual responsive property from PDA alone in a fibrous mat.

Analysis of Drug Release Behavior Utilizing the Swelling Characteristics of Cellulosic Nanofibers.

It is known that the behavior of a drug released from a supporting carrier is influenced by the surrounding environment and the carrier. In this study, we investigated the drug behavior of a swellable electrospun nanofibrous membrane. Nanofibrous mats with different swelling ratios were prepared by mixing cellulose acetate (CA) and polyurethane (PU). CA has excellent biocompatibility and is capable of high water uptake, while PU has excellent mechanical properties. Paclitaxel (PTX) was the drug of choice for observing drug release behavior, which was characterized by UV-spectroscopy. FE-SEM was used to confirm the morphology of the nanofibrous mats and to measure the average fiber diameters. We observed a noticeable increase in the total volume of the nanofibrous membrane when it was immersed in water. Also, the drug release behavior increased proportionally with increasing swelling rate of the composite nanofibrous mat. Biocompatibility testing of nanofiber materials was confirmed by CCK-8 assay and cell morphology was observed. Based on these results, we propose nanofibrous mats as promising candidates in wound dressing and other drug carrier applications.

Nature derived scaffolds for tissue engineering applications: Design and fabrication of a composite scaffold incorporating chitosan-g-d,l-lactic acid and cellulose nanocrystals from Lactuca sativa L. cv green leaf.

Through exhaustive extraction via successive alkali and bleaching treatments cellulose was isolated from lettuce. The isolated cellulose was hydrolyzed using 64wt% H2SO4 at 55°C under constant stirring for 1h to obtain cellulose nanocrystals (CNCs). Characterizations such as SEM, TEM, FTIR, TGA and XRD were done in order to determine differences in the physico-chemical characteristics of cellulose after each treatment step. The isolated CNCs have mean dimensions of 237±26, 33±12 and 32±7nm in length, thickness and height, respectively. These nanocrystals were incorporated to the formulations that were used to fabricate different chitosan-g-d,l-lactic acid (CgLA) scaffolds. Amide linkage formation between chitosan and lactic acid and further removal of water was facilitated by oven-drying under vacuum at 80°C. Results show that an increase in the concentration of CNCs added, increase in porosity, degradability, drug release property and cell viability were observed from the fabricated composite scaffolds. These results can provide information on how nanofillers such as CNCs can alter the properties of tissue scaffolds through the chemical properties and interactions they provide. Moreover, these characteristics can give new properties that are necessary for certain tissue engineering applications.

Development of bioactive cellulose nanocrystals derived from dominant cellulose polymorphs I and II from Capsosiphon Fulvescens for biomedical applications.

Cellulose I and II polymorphs were isolated from Capsosiphon fulvescens (CF) using the conventional method of extraction and direct mercerization of raw sample, respectively. The morphological and structural differences between the isolated polymorphs were studied by FTIR, FESEM and XRD. Direct mercerization of raw CF yielded the transformation of highly crystalline cellulose I (81.3%) to II (63.7%) as observed in the shifting of XRD patterns. The derived cellulose I and II were hydrolyzed (60% w/w H2SO4, 55°C, 1h, 10mL/g) to obtain the spindle-shaped cellulose nanocrystals. Cellulose nanocrystal I was observed to have a mean thickness and length of 12.67±2.69 and 92.31±21.31nm, respectively; while cellulose nanocrystal II has a mean thickness and length of 15.58±2.85 and 78.09±18.22nm, respectively. Furthermore, a fiber-like mat assembly, which could be used as supplement support structure for tissue engineering, was obtained after subjecting the aqueous cellulose nanocrystal suspensions to freeze-drying. A possible application of this material can be as a biocompatible and biodegradable composite for tissue engineering and other biomedical applications.

Development of polyamide-6,6/chitosan electrospun hybrid nanofibrous scaffolds for tissue engineering application.

The development of biofunctional and bioactive hybrid polymeric scaffolds seek to mitigate the current challenges in the emerging field of tissue engineering. In this paper, we report the fabrication of a biomimetic and biocompatible nanofibrous scaffolds of polyamide-6,6 (PA-6,6) blended with biopolymer chitosan via one step co-electrospinning technique. Different weight percentage of chitosan 10wt%, 15wt%, and 20wt% were blended with PA-6,6, respectively. The nanocomposite electrospun scaffolds mats enabled to provide the osteophilic environment for cells growth and biomineralization. The morphological and physiochemical properties of the resulted scaffolds were studied using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Fourier transform-infrared (FT-IR) spectroscopy. The improvement in hydrophilicity and mechanical strength of the bio-nanocomposite mesh with 20wt% chitosan embedded, was the desired avenue for adhesion, proliferation and maturation of osteoblast cells as compared to other sample groups and pure PA-6,6 fibrous mat. The biomineralization of the nanocomposite electrospun mats also showed higher ability to nucleate bioactive calcium phosphate (Ca/P) nanoparticles comparing to pristine PA-6,6. Furthermore, the biomimetic nature of scaffolds exhibited the cells viability and regeneration of pre-osteoblast (MC3T3-E1) cells which were assessed via in vitro cell culture test. Collectively, the results suggested that the optimized 20wt% of chitosan supplemented hybrid electrospun fibrous scaffold has significant effect in biomedical field to create osteogenic capabilities for tissue engineering.