Chao Tsang Lu

Property evaluation of Bletilla striata /polyvinyl alcohol nano fibers and composite dressings

This study used nonwoven manufacture and electrospinning to create wound dressings with solid mechanical properties and hemostasis function. 10% Polyvinyl alcohol (PVA) and 5% Bletilla striata (BS) were blended into the PVA/BS solution, which can be made into nanomaterial with high specific surface area by electrospinning. The PVA/BS solution was electrospun onto the dressing matrix made of polyester (PET) and absorbent cotton (AC), forming the PVA/BS composite dressings. According to the experiment results, when the volume ratio of PVA to BS was 9 : 1, the resulting dressings had optimal fiber formation, the finest average diameter, and the lowest toxicity.

Novel Manufacturing Process for Tencel/Chitosan/Pectin Composite Dressing

The treatment for wound is a common issue in nursing procedure. Especially in serious wound, the treatment for wound usually spends many costs and time. Generally, wound dressing is used to protect the wound from bacterial infection in the intervening period between hospitalization and grafting. The pectin and chitosan are natural polymers that have biocompatibility and biodegradability, and pectin and chitosan can be easy obtainment and low cost. Tencel is a regenerated fiber. The Tencel fibers are biodegradable and hydrophilic, and have stable capability of dimension. Therefore, if the pectin and chitosan can be properly developed and combine with the tencel fabric for dressing use, the cost and time for wound treatment could be effective reduction. The absorbent cotton fibers were blended with the tencel fibers to create the cotton/Tencel nonwoven substance using nonwoven manufacturing technique. Chitosan will be electrospun on the Tencel nonwoven substance to create chitosan/Tencel composite nonwoven fabric. Furthermore, the surface structure of chitosan/Tencel composite nonwoven was observed by using scanning electron microscopy (SEM) to examine spinning ability of chitosan. Additionally, the pectin solution was blended with calcium chloride solution. Then pectin blended solution was coated on the optimal chitosan/Tencel composite nonwoven fabric by using mesh printing technique to prepare composite dressing. The result shown the Tencel/chitosan/pectin composite dressing has good capabilities of water absorbency and evaporative water loss. This study showed that a novel process for medical dressing was useful, and the composite dressing had an advantage property on wound healing and protection.

Preparation and evaluation of artificial bone complex material: chitosan/polylactic complex braids

Polymer has been widely applied in the biomedical field. In this study, degradable polylactic complex yarns are twisted and braided by a 16-spindle braid machine; therefore, a polylactic complex braid fabric, an artificial bone material, was prepared. Different experimental parameters were conducted to examine the complex braid fabric’s mechanical property. chitosan was coated onto the polylactic braid as a membrane. The modified chitosan produced a functional group existing on its surface. This polylactic complex braid was immersed in the simulated body fluid to observe Hap. When the modified chitosan/polylactic complex braid was immersed in the simulated body fluid for 21 days, the overall hydroxyapatite was in sphere shape as previous studies had argued.Polymer has been widely applied in the biomedical field. In this study, degradable polylactic complex yarns are twisted and braided by a 16-spindle braid machine; therefore, a polylactic complex braid fabric, an artificial bone material, was prepared. Different experimental parameters were conducted to examine the complex braid fabric’s mechanical property. chitosan was coated onto the polylactic braid as a membrane. The modified chitosan produced a functional group existing on its surface. This polylactic complex braid was immersed in the simulated body fluid to observe Hap. When the modified chitosan/polylactic complex braid was immersed in the simulated body fluid for 21 days, the overall hydroxyapatite was in sphere shape as previous studies had argued.

Preparation and Evaulation of Degradable Poly(lactic acid) Composite Dressings

Chitosan and sodium alginate are two prominent biomaterials because they have some unique properties such as good biocompatible and biodegradable. In this study, sodium alginate was as swelling and moisture retention layer; Chitosan was antibacterial layer.Polylactic acid (PLA) blended in different weight ratios with low melting point polylactic acid (LMPLA) to fabricate nonwoven fabric which reinforced by needle punching and hot pressing. Afterward, chitosan/ sodium alginate compound solution were treated by UV light in order to form cross-linking. Then chitosan/ sodium alginate compound solution coated on the PLA nonwoven fabric to make PLA composite dressings. The mechanical properties of chitosan/ sodium alginate membrane and dressing were measured. The optimum parameters of chitosan/sodium alginate composite membrane was treated by UV light for five minutes and the volume ratio of chitosan (3 wt %) and sodium alginate (1 wt %) solution was 8:2. After we coated chitosan/sodium alginate solution on PLA nonwoven fabric, the Tensile strength, and tear strength were upgraded by 80 % and 98 %; its air permeability and flexibility length, however, dropped by 18 % and 60 %, respectively.

Preparation and applications of polyamide 6/IRM® tooth root composite filling material

Intermediate restorative material (IRM®) is the most commonly used temporary filling material. This research mixed IRM with Polyamide 6 (Nylon 6) fibers, forming the Nylon/IRM tooth root composite filling materials. Tests such as setting time, degree of solubility, compressing strength, and micro-leakage were carried out to examine the properties of the Nylon 6/IRM® composite material. The result showed that there was no significant difference in the setting time and degree of solubility after adding the Nylon 6 fibers. The loading after the yielding point of the Nylon 6/IRM® was more than 250 N; micro-leakage was found on the 13th day.

Preliminary Studies in Composite Scaffolds of Calcium Phosphate Bone Cement with Polylactide

Calcium phosphate bone cement (CPC), a ceramic material, is commonly used as a biomaterial for the restoration of bone injuries. This study creates the composite scaffolds by mixing CPC with various amounts of polylactide fibers. Then, the resulting scaffolds are observed and tested in terms of the morphology, compressive strength, and fiber distribution, respectively, to explore the influence of the addition of polylactide fibers on the scaffolds. According to the experimental result, the compressive strength of the scaffolds increases as a result of an increase in the addition of fibers.

Preparation and Characterization of Polyester Fibers/Absorbent Cotton Composite Dressing Matrix Fabrics

In this study, the polyester fiber (PET) and absorbent cotton (AC) blend was needle-bonded to make the nonwoven PET/AC composite wound dressing matrix fabrics. The combined advantages of mechanical strength due to PET and water absorption due to AC make the composite nonwoven an attracting wound dressing matrix fabric. We examined physical features, such as mechanical properties, air permeability, softness, water imbibition, and water absorption rate, of the nonwovens made of different blending ratios of PET and AC. We found that while the strength and air permeability were slightly reduced at blending ratio of 80:20, the water imbibition increased about 1.6 cm for the same nonwoven. The results suggested that the optimal blending ratio for the nonwoven to be used as a wound dressing matrix is 80:20.

Evaluation of the Preparation and Biocompatibility of Poly(vinyl Alcohol)(PVA)/Chitosan Composite Electrospun Membranes

Electrospinning has been used in a wide variety of applications, such as tissue engineering, filtration and biomaterial scaffolds for vascular grafts or wound dressings. Recently, wound dressings have become more important in human life. They must have the superior biocompatibility, water absorption, water vapor permeation and antibacterial ability. Chitosan has been employed in clinical applications and exhibits excellent biocompatibility, biodegradation and bacteriostasis. In this investigation OR study, experiments were performed on a series of poly (vinyl alcohol) (PVA)/Chitosan (CS) fiber membranes at various blend ratios and electric fields to evaluate their spinnability. The morphology, diameter and structure of electrospun nanofibers were examined by scanning electron microscopy (SEM). When PVA/Chitosan=80:20 and electric field=0.67 kV/cm, the spinnability of electrospun membrane was good. IR spectra demonstrated strong intermolecular hydrogen bonds between the molecules of Chitosan and PVA. Furthermore, cell cultures demonstrate that both PAV and chitosan have good biocompatibility and are non-toxic.

Manufacturing Processing of Polylactic Acid Braids as Artificial Bone Matrix

In this study, the PLA plied yarn was fabricated by twisting four of PLA yarns together, then PLA plied yarn was used a 16-spindle braid machine to produce the PLA braids. PLA braids were immersed in the suspension of β-tricalcium phosphate (β-TCP), and heat treatment to improve the adhesion of β-TCP particles. PLA/β-TCP composite braids were immersed in simulated body fluid (SBF) to promote bonelike apatite production. The morphology of PLA braids were investigated by scanning electron microscopy (SEM), and the results shown that when twist coefficient was 3 of PLA plied yarn, the concentration of β-TCP suspension was 0.15 wt % and heat treatment at 175 °C for 9 min, we can obtain the optimal conditions of β-TCP particles adhesion.

Compressive Strength of Porous Bone Cement/Polylactic Acid Composite Bone Scaffolds

Calcium phosphate bone cement (CPC), a bioceramic, is commonly used in artificial bone scaffold for impaired bones. In this study, CPC is mixed with polylactide (PLA) fibers and porogenic agent to form CPC/PLA composite bone scaffold. The compressive strength of the resulting bone scaffolds is evaluated and the fractured cross-section is observed by a scanning electron microscope (SEM), thereby determining the influence of fiber length. The experimental results show that the shorter the fiber is, the greater the compressive strength is.