Synthesis of novel cellulose based composite fibers by electrospinning technique

Abstract

High performance topical plasma coagulation material was developed using cellulose and halloysite nanoclay (Al2Si2O5(OH)4.2H2O). This cellulose - halloysite hemostatic nanocomposite fibers (CHNFs), were fabricated using a one-step wet-wet electrospinning process. The coagulation activity was evaluated by activated Partial Thromboplastin Time (aPTT) and was 2.4 times faster than aPTT of Quikclot Combat Gauze® (QCG®), the gold standard procoagulant fibers currently in clinical use. The application of this CHNF composite is envisioned for victims of rapid blood loss, including military personnel and patients undergoing major surgical procedures, and for the treatment of unexpected bleeding episodes of patients suffering from hereditary blood clotting disorders.

The physical characteristics of all the nanocomposite fibers prepared in the current studies were evaluated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) surface area analysis. Furthermore, all the nanocomposite fibers were subjected to thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) to study the thermal properties of these novel materials.

Another novel, composite prepared was a phase-change material developed for the conversion of thermal energy into latent heat for use in thermoregulation. These composite fibers were fabricated using the melt-coaxial electrospinning technique to encapsulate the phase change material, coconut oil, into a cellulose matrix. A favorable increase in the heat capacities of the phase change material was observed on mesoscale confinement. These findings should lead to advances in the area of composite phase change cellulose fibers for a variety of sustainable products such as wearable thermoregulating textiles, wall/ceiling panels, insulation, and packaging material. The broad applicability of this novel thermoregulating ecofriendly material and insights gained through thermal analyses will provide critical guidance for researchers interested in developing cellulose based core-shell phase change fibers with improved efficacy.

Magnetically responsive heparin-immobilized cellulose nanofibers were one of the successfully created cellulose composites. Co-axial electrospinning technique was employed to localize the magnetite nanoparticles in the core of cellulose fibers to isolate these from the external environment. Anticoagulant glycosaminoglycan, heparin, was covalently attached to the surface of the cellulose fibers to prevent leaching of heparin in to the surroundings. The heparin-cellulose-magnetite composite was then analyzed using liquid chromatography-mass spectrometry (LC-MS) and Fourier transform infrared spectroscopy (FT-IR) to confirm the presence of heparin in the fibers. Antifactor Xa and antifactor IIa assays were then used to evaluates the anticoagulant activity of the immobilized heparin in the composite fibers. This novel nanofibrous polymeric material has the potential of being used in a broad range of biomedical applications including the separation of heparin binding proteins from blood samples and medical implant devices.

Novel biodegradable composite fibers were fabricated using an electrospinning technique. Cellulose was selected as the base material due to its higher abundance and tensile strength. Room temperature ionic liquid was used to dissolve cellulose and made into nano or micro fibers by wet-wet electrospinning technique. A wide variety of materials were incorporated in these fibers to create cellulose with unique and innovative characteristics. Some of these materials included inorganic compounds such as superparamagnetic magnetite nanoparticles (Fe3O4) and halloysite nanoclay (Al2Si2O5(OH)4.2H2O). Organic materials are also been subsumed in to fibers to impart novel properties to the cellulose composites. Heparin and coconut oil are examples of such materials.