Using biopolymers as wall materials in spray drying poses challenges,particularly in attaining flowability and thermal stability among their physicochemical properties.This paper addresses these challenges by preparin...Using biopolymers as wall materials in spray drying poses challenges,particularly in attaining flowability and thermal stability among their physicochemical properties.This paper addresses these challenges by preparing microparticles using a blend of starch–chitosan and a poloxamer,commercially named Pluronic®F127.We aimed to elucidate the effects of varying poloxamer concentrations on the resulting particles through the spray drying technique.Blends with a poloxamer concentration of 3%(w/v)demonstrated a notably higher yield,especially when compared to those with 0%and 1%concentrations.Microparticles with 3%and 5%(w/v)poloxamer displayed a narrower particle size distribution,with the 3%blend showing a superior yield attributed to arrangements of blend components that improve flowability.X-ray diffraction analysis showcased the characteristic peaks of A-type starch form,with shifts suggesting enhanced interactions between components.Microparticles with increased poloxamer content showed elevated thermal degradation temperatures,with the 3%blend registering a significant rise,opening avenues for encapsulating heat-sensitive bioactive.This study primarily focuses on the preparation and basic characterization of microparticles.It underscores the potential of blends with optimal poloxamer concentrations in microencapsulation,emphasizing further research to harness their capabilities thoroughly.展开更多
Brachial plexus avulsion often results in massive motor neuron death and severe functional deficits of target muscles. However, no satisfactory treatment is currently available. Hypoxia-inducible factor 1α is a criti...Brachial plexus avulsion often results in massive motor neuron death and severe functional deficits of target muscles. However, no satisfactory treatment is currently available. Hypoxia-inducible factor 1α is a critical molecule targeting several genes associated with ischemia-hypoxia damage and angiogenesis. In this study, a rat model of brachial plexus avulsion-reimplantation was established, in which C5–7 ventral nerve roots were avulsed and only the C6 root reimplanted. Different implants were immediately injected using a microsyringe into the avulsion-reimplantation site of the C6 root post-brachial plexus avulsion. Rats were randomly divided into five groups: phosphate-buffered saline, negative control of lentivirus, hypoxia-inducible factor 1α(hypoxia-inducible factor 1α overexpression lentivirus), gel(pluronic F-127 hydrogel), and gel + hypoxia-inducible factor 1α(pluronic F-127 hydrogel + hypoxia-inducible factor 1α overexpression lentivirus). The Terzis grooming test was performed to assess recovery of motor function. Scores were higher in the hypoxia-inducible factor 1α and gel +hypoxia-inducible factor 1α groups(in particular the gel + hypoxia-inducible factor 1α group) compared with the phosphate-buffered saline group. Electrophysiology, fluorogold retrograde tracing, and immunofluorescent staining were further performed to investigate neural pathway reconstruction and changes of neurons, motor endplates, and angiogenesis. Compared with the phosphate-buffered saline group, action potential latency of musculocutaneous nerves was markedly shortened in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor1α groups. Meanwhile, the number of fluorogold-positive cells and ChAT-positive neurons, neovascular area(labeled by CD31 around av ulsed sites in ipsilateral spinal cord segments), and the number of motor endplates in biceps brachii(identified by α-bungarotoxin) were all visibly increased, as well as the morphology of motor endplate in biceps brachil was clear in the hypoxia-i展开更多
基金supporting the financing of this study through project 6710(Internal call 2022).
文摘Using biopolymers as wall materials in spray drying poses challenges,particularly in attaining flowability and thermal stability among their physicochemical properties.This paper addresses these challenges by preparing microparticles using a blend of starch–chitosan and a poloxamer,commercially named Pluronic®F127.We aimed to elucidate the effects of varying poloxamer concentrations on the resulting particles through the spray drying technique.Blends with a poloxamer concentration of 3%(w/v)demonstrated a notably higher yield,especially when compared to those with 0%and 1%concentrations.Microparticles with 3%and 5%(w/v)poloxamer displayed a narrower particle size distribution,with the 3%blend showing a superior yield attributed to arrangements of blend components that improve flowability.X-ray diffraction analysis showcased the characteristic peaks of A-type starch form,with shifts suggesting enhanced interactions between components.Microparticles with increased poloxamer content showed elevated thermal degradation temperatures,with the 3%blend registering a significant rise,opening avenues for encapsulating heat-sensitive bioactive.This study primarily focuses on the preparation and basic characterization of microparticles.It underscores the potential of blends with optimal poloxamer concentrations in microencapsulation,emphasizing further research to harness their capabilities thoroughly.
基金financially supported by the National Natural Science Foundation of China,No.81371366(to HFW)the Natural Science Foundation of Guangdong Province of China,No.2015A030313515(to HFW)+1 种基金the Dongguan International Science and Technology Cooperation Project,No.2013508152010(to HFW)the Key Project of Social Development of Dongguan of China,No.20185071521640(to HFW)
文摘Brachial plexus avulsion often results in massive motor neuron death and severe functional deficits of target muscles. However, no satisfactory treatment is currently available. Hypoxia-inducible factor 1α is a critical molecule targeting several genes associated with ischemia-hypoxia damage and angiogenesis. In this study, a rat model of brachial plexus avulsion-reimplantation was established, in which C5–7 ventral nerve roots were avulsed and only the C6 root reimplanted. Different implants were immediately injected using a microsyringe into the avulsion-reimplantation site of the C6 root post-brachial plexus avulsion. Rats were randomly divided into five groups: phosphate-buffered saline, negative control of lentivirus, hypoxia-inducible factor 1α(hypoxia-inducible factor 1α overexpression lentivirus), gel(pluronic F-127 hydrogel), and gel + hypoxia-inducible factor 1α(pluronic F-127 hydrogel + hypoxia-inducible factor 1α overexpression lentivirus). The Terzis grooming test was performed to assess recovery of motor function. Scores were higher in the hypoxia-inducible factor 1α and gel +hypoxia-inducible factor 1α groups(in particular the gel + hypoxia-inducible factor 1α group) compared with the phosphate-buffered saline group. Electrophysiology, fluorogold retrograde tracing, and immunofluorescent staining were further performed to investigate neural pathway reconstruction and changes of neurons, motor endplates, and angiogenesis. Compared with the phosphate-buffered saline group, action potential latency of musculocutaneous nerves was markedly shortened in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor1α groups. Meanwhile, the number of fluorogold-positive cells and ChAT-positive neurons, neovascular area(labeled by CD31 around av ulsed sites in ipsilateral spinal cord segments), and the number of motor endplates in biceps brachii(identified by α-bungarotoxin) were all visibly increased, as well as the morphology of motor endplate in biceps brachil was clear in the hypoxia-i
