ABSTRACT
Severe bleeding from deep and irregular wounds poses a significant challenge in prehospital and surgical settings. To address this issue, we developed a novel chitosan-based hemostatic dressing with a magnetic targeting mechanism using Fe3O4, termed bovine serum albumin-modified Fe3O4 embedded in porous α-ketoglutaric acid/chitosan (BSA/Fe3O4@KA/CS). This dressing enhances hemostasis by magnetically guiding the agent to the wound site. In vitro, the hemostatic efficacy of BSA/Fe3O4@KA/CS is comparable to that of commercial chitosan (Celox™) and is not diminished by the modification. In vivo, BSA/Fe3O4@KA/CS demonstrated superior hemostatic performance and reduced blood loss compared to Celox™. The hemostatic mechanism of BSA/Fe3O4@KA/CS includes the concentration of solid blood components through water absorption, adherence to blood cells, and activation of the endogenous coagulation pathway. Magnetic field targeting is crucial in directing the dressing to deep hemorrhagic sites. Additionally, safety assessments have confirmed the biocompatibility and biodegradability of BSA/Fe3O4@KA/CS. In conclusion, we introduce a novel approach to modify chitosan using magnetic guidance for effective hemostasis, positioning BSA/Fe3O4@KA/CS as a promising candidate for managing various wounds.
Subject(s)
Bandages , Chitosan , Hemostatics , Serum Albumin, Bovine , Chitosan/chemistry , Serum Albumin, Bovine/chemistry , Animals , Hemostatics/chemistry , Hemostatics/pharmacology , Porosity , Ketoglutaric Acids/chemistry , Ketoglutaric Acids/pharmacology , Cattle , Male , Hemorrhage/drug therapy , Hemorrhage/therapy , MiceABSTRACT
In order to investigate the effects of different drying methods on the properties of porous starch. The present study used four drying methods, namely hot air drying (HD), spray drying (SPD), vacuum freeze drying (FD) and supercritical carbon dioxide drying (SCD) to prepare maize and kudzu porous starch. Findings indicated that the physicochemical properties (e.g., morphology, crystallinity, enthalpy value, porosity, surface area and water absorption capacity as well as dye absorption capacity, particle size) of porous starch were significantly affected by the drying method. Compared with other samples, SCD-treated porous starch exhibited the highest surface areas of the starch (2.943 and 3.139 m2/g corresponding to kudzu and maize, respectively), amylose content (22.02 % and 16.85 % corresponding to kudzu and maize, respectively), MB and NR absorption capacity (90.63 %, 100.26 % and 90.63 %, 100.26 %, corresponding to kudzu ad maize, respectively), and thermal stability, whereas HD-treated porous starch showed the highest water-absorption capacity (123.8 % and 131.31 % corresponding to kudzu and maize, respectively). The dye absorption of the maize and kudzu porous starch was positively correlated with surface area, according to Pearson's correlation analysis. Therefore, in this study, our aim was to explore the effects of different drying methods on the Structure and properties of porous starch, and provide reference for selecting the best drying method for its application in different fields.
ABSTRACT
A traumatic hemorrhage is fatal due to the great loss of blood in a short period of time; however, there are a few biomaterials that can stop the bleeding quickly due to the limited water absorption speed. Here, a highly absorbent polymer (HPA), polyacrylate, was prepared as it has the best structure-effectiveness relationship. Within a very short period of time (2 min), HPA continually absorbed water until it swelled up to its 600 times its weight; more importantly, the porous structure comprised the swollen dressing. This instantaneous swelling immediately led to rapid hemostasis in irregular wounds. We optimized the HPA preparation process to obtain a rapidly water-absorbent polymer (i.e., HPA-5). HPA-5 showed favorable adhesion and biocompatibility in vitro. A rat femoral arteriovenous complete shear model and a tail arteriovenous injury model were established. HPA exhibited excellent hemostatic capability with little blood loss and short hemostatic time compared with CeloxTM in both of the models. The hemostatic mechanisms of HPA consist of fast clotting by aggregating blood cells, activating platelets, and accelerating the coagulation pathway via water absorption and electrostatic interaction. HPA is a promising highly water-absorbent hemostatic dressing for rapid and extensive blood clotting after vessel injury.
ABSTRACT
Tunnel construction often relies on drilling and blasting. High dust pollution is one of the primary problems of drilling and blasting construction. The level of secondary blown dust pollution caused by ventilation matches that of dust pollution caused by drilling construction. In this study, a critical flow model and blown dust rate model for deposited dust were established via force analysis, which was validated against the test data. The research results showed that the characteristic airflow velocity for blowing dust particles with a 100 µm diameter reached approximately 0.42 m/s for tunnel diameter is 10 m, and the ventilation Re values under smooth and rough conditions were 2.3 × 105 and 1.4 × 105, respectively. Furthermore, when ventilation Re reached 4 × 105, the blown dust pollution rate caused by ventilation under smooth conditions was approximately 1.8 × 10-2 kg/s. If dust particle size is more or less the critical dust particle size, the characteristic airflow velocity was increased. Moreover, the optimal velocity at which the deposited dust does not flow or move during tunnel construction was related to the tunnel size and roughness. For the smooth tunnel with a diameter of 10 m, the optimal ventilation velocity was 3.5 m/s. When the tunnel roughness was increased from 0.005 to 0.5 m, the optimal ventilation velocity decreased from 3.3 to 1.6 m/s. The deposited dust critical flow model and blown dust pollution rate model established in this study provide a sound theoretical basis for selecting the optimal velocity of tunnel ventilation and recognizing the risks of secondary blown dust pollution due to ventilation.
Subject(s)
Dust , Occupational Exposure , Dust/analysis , Ventilation/methods , Particle Size , Occupational Exposure/analysis , RespirationABSTRACT
The oil body comprises lipid droplets surrounded by a surface embedded with oil body-related proteins. To form a drug delivery system, an oleosin can be fused with foreign proteins and bound to the oil body surface. Here, safflower oil bodies carrying oleosin-human epidermal growth factor (hEGF) were mixed with xanthan gum to form self-assembled polymers, referred as an oil body microgel emulsion (OBEME) without any chemical crosslinking agent. The physicochemical properties of OBEME were evaluated and compared with those of natural lipid droplets. The electrostatic interaction between xanthan gum and oil bodies prevents excessive cross-linking and forms a uniform network structure. The basic properties of OBEME were characterized by scanning electron microscopy, cryo-scanning electron microscopy, rheology, and thermogravimetric analysis. The OBEME is an interconnected network and presents a smooth surface without any pores; it remains stable at room temperature for 90 days, and is not affected by low-speed centrifugation and repeated freeze-thaw cycles as indicated by particle size, potential, and fluorescence microscopy analyses. The OBEME enlarges the skin tissue gap, enhances skin permeability, and shows a good slow-release effect in the transdermal absorption test in vivo. It demonstrates a wound healing effect; further, it regulates the inflammatory response of full-layer skin wounds in rats, as well as accelerate angiogenesis, and promote re-epithelialization and remodeling. The OBEME as a bioactive molecule-carbohydrate complex can effectively accelerate skin regeneration and has great translational potential to provide low-cost alternative wound care treatments.
Subject(s)
Microgels , Skin Absorption , Humans , Rats , Animals , Emulsions/chemistry , Lipid Droplets , Wound HealingABSTRACT
Regeneration of a part of the diseased liver after surgical resection is mainly achieved by the proliferation of the remaining healthy liver cells. However, in case of extreme loss of liver cells or in the final stages of chronic liver disease, most liver cells are depleted or lose their ability to proliferate. Therefore, to foster liver regeneration, it is of great clinical and scientific significance to improve the survival and proliferation ability of residual hepatocytes. In this study, we conducted experiments on a zebrafish model of targeted ablation of liver cells to clarify the role of fibroblast growth factor 21 (FGF21). We found that FGF21 increased the regeneration area of the damaged liver and improved the survival rate of damaged liver cells by inhibiting cell apoptosis and reducing oxidative stress. Our results also showed that administration of FGF21 upregulated autophagy, and the beneficial effects of FGF21 were reversed by the well-known autophagy inhibitor chloroquine (CQ), indicating that FGF21-activated autophagy played a central role in the treatment. We further showed that the enhancement of autophagy induced by FGF21 was due to the activation of the AMPK-mTOR signaling pathway. Taken together, these data provide new evidence that FGF21 is an effective autophagy regulator that can significantly improve the survival of damaged livers.
ABSTRACT
INTRODUCTION: Oil body (OB), a subcellular organelle that stores oil in plant seeds, is considered a new transdermal drug delivery system. With the increasing understanding of the OB and its main protein (oleosin), numerous studies have been conducted on OB as "carrier" for the expression of exogenous proteins. In our previous study, oil body fused with aFGF (OLAF) was obtained using a plant oil body expression system that had been preliminarily proven to be effective in accelerating the healing of skin wounds. However, no dermal toxicological information on OLAF is available. OBJECTIVE: To ensure the dermal safety of OLAF, a series of tests (the acute dermal toxicity test, 21-day repeat dermal toxicity test, dermal irritation test and skin sensitisation test) were conducted after optimising the extraction protocol of OLAF. MATERIALS AND METHODS: To improve the extraction rate of OLAF, response surface methodology (RSM) was first employed to optimise the extraction conditions. Then, Wistar rats were exposed to OLAF (400 mg·kg-1 body weight) in two different ways (6 hours/time for 24 hours and 1 time/day for 21 days) to evaluate the acute dermal toxicity and 21-day repeated dermal toxicity of OLAF. In the acute dermal toxicity test, clinical observations were conducted to evaluate the toxicity, behaviour, and health of the animals for 14 consecutive days. Similarly, the clinical signs, body weight, haematological and biochemical parameters, histopathological changes and other indicators were also detected during the 21 days administration. For the dermal irritation test, single and multiple doses of OLAF (125 mg·kg-1 body weight) were administered to albino rabbits for 14 days (1 time/day). The irritation reaction on the skin of each albino rabbit was recorded and scored. Meanwhile, skin sensitisation to OLAF was conducted using guinea pigs for a period of 28 days. RESULTS: Suitable extraction conditions for OLAF (PBS concentration 0.01, pH of PBS 8.6, solid-liquid ratio 1:385 g·mL-1) were obtained using RSM. Under these conditions, the extraction rate and particle size of OLAF were 7.29% and 1290 nm, respectively. In the tests of acute dermal toxicity and 21-day repeated dermal toxicity, no mortality or significant differences were observed in terms of clinical signs, body weight, haematological parameters, biochemical parameters and anatomopathological analysis. With respect to the dermal irritation test and skin sensitisation test, no differences in erythema, oedema or other abnormalities were observed between treatment and control groups on gross and histopathological examinations. CONCLUSIONS: The results of this study suggest that OLAF does not cause obvious toxicity, skin sensitisation or irritation in animals.
Subject(s)
Drug Carriers/toxicity , Fibroblast Growth Factor 1/administration & dosage , Lipid Droplets , Plant Oils/isolation & purification , Skin/drug effects , Administration, Cutaneous , Animals , Female , Fibroblast Growth Factor 1/toxicity , Guinea Pigs , Male , Plant Oils/toxicity , Rabbits , Rats , Skin Tests , Toxicity Tests, Acute , Wound Healing/drug effectsABSTRACT
We set out to assess the NIH/3T3 cell proliferation activity of Arabidopsis oil body-expressed recombinant oleosin-hEGF-hEGF protein. Normally, human epidermal growth factor (hEGF) is purified through complex process, however, oleosin fusion technology provides an inexpensive and scalable platform for its purification. Under a phaseolin promoter, we concatenated oleosin gene to double hEGF (hEGF-hEGF) with plant-preferred codons in the expression vectors and the construct was transformed into Arabidopsis thaliana (Arabidopsis). The transgenic Arabidopsis was validated by RT-PCR and the content of recombinant protein oleosin-hEGF-hEGF was quantified by western blot. Subsequently, the proliferation assay and transdermal absorption were determined by MTT method and immunohistochemical staining, respectively. First, the expression level of hEGF was recorded to be 14.83-ng/µL oil body and due to smaller size transgenic oil bodies expressing the recombinant oleosin-hEGF-hEGF, they were more skin permeable than those of control. Second, via the staining intensity of transgenic oil bodies was greater than EGF at all time points via immunohistochemical staining in transdermal absorption process. Lastly, activity assays of oil bodies expressed oleosin-hEGF-hEGF indicated that they stimulated the NIH/3T3 cell proliferation activity. Our results revealed oil-body-expressed oleosin-hEGF-hEGF was potential new material having implications in the field of medicine.