Engineered commensals for targeted nose-to-brain drug deliveryIntranasal administration through the olfactory epithelium (OE) presents a direct pathway for brain-targeted therapeutic delivery, although its feasibility is hampered by the anatomical and absorptive limitations of the OE. In this study, we identified Lactobacillus plantarum WCFS1 (Lp), a commensal strain with a natural affinity for the OE and engineered it to function as a vector for cerebral drug delivery. Upon intranasal administration, Lp released specific payload molecules within the OE, with subsequent transport and accumulation in the brain. The therapeutic efficacy of Lp was further validated by the recombinant production and secretion of appetite-regulating hormones. When administered intranasally in a murine model of obesity prevention, the engineered Lp significantly alleviated obesity-related symptoms. This was evidenced by decreased appetite, reduced body weight gain, and improved glucose metabolism and fat mass deposition. Our study demonstrates the capability of Lp as an intranasal delivery vehicle, emphasizing its potential for brain-targeted therapeutic applications.
Gradient Hydrogel Construct Based on an Improved Cell Assembling SystemShengjie Li, Yongnian Yan, Zhuo Xiong et al.|Journal of Bioactive and Compatible Polymers|2009 In this study, a two-step crosslinking method derived from commercial rapid prototyping equipment was used to fabricate a gradient hydrogel scaffold in vitro. This system contained two types of nozzles; one was double-nozzle unit, used for relatively simple gradient hydrogel scaffold composed of two nonmiscible hydrogel materials. The other was single nozzle that was used for mixing a gradient hydrogel scaffold composed of two types of hydrogel materials. Different types of scaffolds were formed by modifying the gradient in one of the relevant nozzles. To improve the extrusion controlling effect, accessorial parameters were introduced. A 3D gradient construct containing neuron cells and Schwann cells was fabricated and cultured for 7 days. This construct was helpful in designing a gradient mode to observe the relationship between different cells in vitro. This work has improved tissue-engineering techniques for later manufacturing of very complicated organ analogs.
Tai Chi for Essential HypertensionJie Wang, Bo Feng, Xiaochen Yang et al.|Evidence-based Complementary and Alternative Medicine|2013 Objectives. To assess the current clinical evidence of Tai Chi for essential hypertension (EH). Search Strategy. 7 electronic databases were searched until 20 April, 2013. Inclusion Criteria. We included randomized trials testing Tai Chi versus routine care or antihypertensive drugs. Trials testing Tai Chi combined with antihypertensive drugs versus antihypertensive drugs were also included. Data Extraction and Analyses. Study selection, data extraction, quality assessment, and data analyses were conducted according to the Cochrane standards. Results. 18 trials were included. Methodological quality of the trials was low. 14 trials compared Tai Chi with routine care. 1 trial compared Tai Chi with antihypertensive drugs. Meta-analysis all showed significant effect of TaiChi in lowering blood pressure (BP). 3 trials compared Tai Chi plus antihypertensive drugs with antihypertensive drugs. Positive results in BP were found in the other 2 combination groups. Most of the trials did not report adverse events, and the safety of Tai Chi is still uncertain. Conclusions. There is some encouraging evidence of Tai Chi for EH. However, due to poor methodological quality of included studies, the evidence remains weak. Rigorously designed trials are needed to confirm the evidence.
Prodrug-conjugated tumor-seeking commensals for targeted cancer therapyHaosheng Shen, Changyu Zhang, Shengjie Li et al.|Nature Communications|2024 Prodrugs have been explored as an alternative to conventional chemotherapy; however, their target specificity remains limited. The tumor microenvironment harbors a range of microorganisms that potentially serve as tumor-targeting vectors for delivering prodrugs. In this study, we harness bacteria-cancer interactions native to the tumor microbiome to achieve high target specificity for prodrug delivery. We identify an oral commensal strain of Lactobacillus plantarum with an intrinsic cancer-binding mechanism and engineer the strain to enable the surface loading of anticancer prodrugs, with nasopharyngeal carcinoma (NPC) as a model cancer. The engineered commensals show specific binding to NPC via OppA-mediated recognition of surface heparan sulfate, and the loaded prodrugs are activated by tumor-associated biosignals to release SN-38, a chemotherapy compound, near NPC. In vitro experiments demonstrate that the prodrug-loaded microbes significantly increase the potency of SN-38 against NPC cell lines, up to 10-fold. In a mouse xenograft model, intravenous injection of the engineered L. plantarum leads to bacterial colonization in NPC tumors and a 67% inhibition in tumor growth, enhancing the efficacy of SN-38 by 54%.
Research on Assisting Clinicians to Operate rTMS Precisely Based on the Coil Magnetic Field Spatial Distribution With Magnetic Resonance Imaging NavigationShijun Li, Yi Wang, Shengjie Li et al.|Frontiers in Neuroscience|2019 OBJECTIVE: To assist clinicians to operate repetitive Transcranial Magnetic Stimulation (rTMS) precisely based on the coil magnetic field spatial distribution with Magnetic Resonance Imaging (MRI) Navigation. METHODS: A fast method for calculating electromagnetic fields in layered brain structures in frequency domain was proposed. By approaching Bessel function in different intervals, the integral with a highly oscillatory kernel was transformed into two parts: a definite integral and a weakened oscillatory one. The distribution of induced current density and magnetic field intensity of rTMS stimulation effect on brain was quantitatively calculated, so that clinicians could intuitively grasp the safe range of coil stimulation on brain. Then, the crucial factor of the stimulation effect of rTMS was determined, and an accurate coil positioning of the rTMS efficiently was completed. Result: The maximal attenuation of induced electric field and magnetic induction intensity was 72.20% and 86.867% at 3 cm away from the skin in the brain layered model. The clinical examination results of electric field intensity distribution, magnetic field intensity distribution, current density distribution, layered brain modeling and coil location speed in the brain model teaching group were significantly higher than those in the traditional teaching group (P < 0.001). CONCLUSION: It is suitable for clinicians to quickly complete the precise positioning of rTMS, master the adjustment of coil stimulation therapeutic parameters, and realize the precise positioning operation of rTMS with MRI navigation in intracranial.