Development of multifunctional chitosan-based composite film loaded with tea polyphenol nanoparticles for strawberry preservation.

Incorporating polysaccharide-based composite films with nanobiotechnology offers a new strategy for food preservation. This study initially focuses on the preparation of tea polyphenol nanoparticles (TPNP), novel and derived from natural antibacterial agents, which serve to improve stability. Afterwards chitosan-based composite films loaded with TPNP (CTN film) were developed using solution casting method. The incorporation of TPNP significantly improved the UV/water/oxygen barrier properties, mechanical properties and thermal stability, alongside notable physical properties including water contact angle (93.65 ± 0.04°), low water vapor permeability (33.72 ± 3.32 g/m2h) and oxygen permeability (0.11 ± 0.02 g/m2h), tensile strength (61.83 ± 0.70 %), and elongation at break (31.60 ± 6.12 %). The CTN film not only exhibited exceptional biodegradability and nontoxicity, but also demonstrated remarkable antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Additionally, it showcased potent antioxidant activity, boasting DPPH and ABTS radical scavenging rates up to 89.25 ± 0.18 % and 93.84 ± 0.42 %. The CTN film was successfully formed on the surface of strawberries through dip-coating process and their shelf life was extended from 4 to 6 days at 20 °C without side-effect on the weight loss, harness, pH and total soluble solids, illustrating its potential for enhancing food preservation.

Morin-Based Nanoparticles for Regulation of Blood Glucose.

Morin, a naturally occurring bioactive compound shows great potential as an antioxidant, anti-inflammatory agent, and regulator of blood glucose levels. However, its low water solubility, poor lipid solubility, limited bioavailability, and rapid clearance in vivo hinder its application in blood glucose regulation. To address these limitations, we report an enzymatically synthesized nanosized morin particle (MNs) encapsulated in sodium alginate microgels (M@SA). This approach significantly enhances morin's delivery efficiency and therapeutic efficacy in blood glucose regulation. Utilizing horseradish peroxidase, we synthesized MNs averaging 305.7 ± 88.7 nm in size. These MNs were then encapsulated via electrohydrodynamic microdroplet spraying to form M@SA microgels. In vivo studies revealed that M@SA microgels demonstrated prolonged intestinal retention and superior efficacy compared with unmodified morin and MNs alone. Moreover, MNs notably improved glucose uptake in HepG2 cells. Furthermore, M@SA microgels effectively regulated blood glucose, lipid profiles, and oxidative stress in diabetic mice while mitigating liver, kidney, and pancreatic damage and enhancing anti-inflammatory responses. Our findings propose a promising strategy for the oral administration of natural compounds for blood glucose regulation, with implications for broader therapeutic applications.

Efficient oral delivery of resveratrol-loaded cyclodextrin-metal organic framework for alleviation of ulcerative colitis.

Developing innovative strategies for the oral administration of phytochemicals presents a promising approach to addressing intestinal diseases. However, numerous challenges persist, including limited therapeutic efficacy, poor bioavailability, and inadequate biocompatibility. In this study, we employed a cross-linked cyclodextrin-metal organic framework (CDF) to encapsulate resveratrol (Res), generating Res-CDF, which was subsequently incorporated into natural polysaccharide hydrogel microspheres (Res-CDF in MPs) for targeted oral delivery to alleviate ulcerative colitis (UC). The underlying adsorption mechanism of Res by γ-CD elucidated by molecular dynamics simulations. Importantly, the Res-CDF in MPs formulation protected against gastric acid degradation while preserving the bioactivity of Res. Moreover, the design enabled specific release of Res-CDF in response to the mildly alkaline environment of the intestinal tract, followed by sustained Res release. In UC mice model, Res-CDF in MPs demonstrated potent anti-inflammatory effects by attenuating pro-inflammatory cytokine production and exhibited antioxidant properties. Additionally, Res-CDF in MPs enhanced the expression of tight junction proteins ZO-1, Occludin, and mucin-2 (Muc-2), thereby maintaining normal intestinal barrier function. This innovative oral delivery strategy capitalizes on the advantageous properties of polysaccharide hydrogel and CDF to augment bioavailability of phytochemicals, laying the groundwork for developing novel oral interventions employing natural phytochemicals to address intestinal-related diseases.

Helical-Like Assembly of Nateglinide as Coating for Oral Delivery of Insulin and Their Synergistic Prevention of Diabetes Mellitus.

Oral delivery of antidiabetic active components promises to free millions of people from daily suffering who require routine injections. However, oral insulin (Ins) and other short-acting compounds such as nateglinide (NG) in harsh gastrointestinal tract still face great challenging, including low bioavailability, and rapid elimination. In this study, inspired by the self-assembly of phenylalanine-based peptides in nature, it is showed that NG a small phenylalanine derivative, assembles into left-handed helical nanofibers in the presence of Ca2+ . These helical NG nanofibers functioned as a coating layer on the surface of Ca2+ -linked alginate (Alg) microgels for the effective encapsulation of Ins. As expected, the sustained release and prolonged circulation of Ins and NG from the Ins-loading Alg/NG microgels (Ins@Alg/NG) in the intestinal tract synergistically maintain a relatively normal blood glucose level in streptozotocin-induced diabetic mice after oral administration of Ins@Alg/NG. This further confirms that Ins@Alg/NG ameliorated Ins resistance mainly through activating Insreceptor substrate 1 (IRS1), protein kinase B (AKT), and AMP-activated protein kinase (AMPK), as well as by repressing glycogen synthase kinase-3ß (GSK-3ß). The strategy of using the assembly of NG as a coating achieves the oral delivery of insulin and showcases a potential for the treatment of diabetes.

Modeling human retinoblastoma using embryonic stem cell-derived retinal organoids.

Retinoblastoma (Rb) is the most prevalent intraocular malignancy in early childhood. Traditional models are unable to accurately recapitulate the origin and development of human Rb. Here, we present a protocol to establish a novel human Rb organoid (hRBO) model derived from genetically engineered human embryonic stem cells (hESCs). This hRBO model exhibits properties highly consistent with human primary Rb and can be used effectively for dissecting the origination and pathogenesis of Rb as well as for screening of potential therapies. For complete details on the use and execution of this protocol, please refer to Liu et al. (2020).

Genotype-Phenotype Analysis and Mutation Spectrum in a Cohort of Chinese Patients With Congenital Nystagmus.

Purpose: Congenital nystagmus (CN) is a genetically and clinically heterogeneous ocular disorder that manifests as involuntary, periodic oscillations of the eyes. To date, only FRMD7 and GPR143 have been reported to be responsible for causing CN. Here, we aimed to identify the disease-causing mutations and describe the clinical features in the affected members in our study. Methods: All the subjects underwent a detailed ophthalmic examination. Direct sequencing of all coding exons and splice site regions in FRMD7 and GPR143 and a mutation assessment were performed in each patient. Results: We found 14 mutations in 14/37 (37.8%) probands, including nine mutations in the FRMD7 gene and five mutations in the GPR143 gene, seven of which are novel, including c.284G>A(R95K), c.964C>T(P322S), c.284+10T>G, c.901T>C (Y301H), and c.2014_2023delTCACCCATGG(S672Pfs*12) in FRMD7, and c.250+1G>C, and c.485G>A (W162*) in GPR143. The mutation detection rate was 87.5% (7/8) of familial vs. 24.1% (7/29) of sporadic cases. Ten mutations in 24 (41.7%) non-syndromic subjects and 4 mutations in 13(30.8%) syndromic subjects were detected. A total of 77.8% (7/9) of mutations in FRMD7 were concentrated within the FERM and FA domains, while all mutations in GPR143 were located in exons 1, 2, 4 and 6. We observed that visual acuity tended to be worse in the GPR143 group than in the FRMD7 group, and no obvious difference in other clinical manifestations was found through comparisons in different groups of patients. Conclusions: This study identified 14 mutations (seven novel and seven known) in eight familial and 29 sporadic patients with congenital nystagmus, expanding the mutational spectrum and validating FRMD7 and GPR143 as mutation hotspots. These findings also revealed a significant difference in the screening rate between different groups of participants, providing new insights for the strategy of genetic screening and early clinical diagnosis of CN.

Human embryonic stem cell-derived organoid retinoblastoma reveals a cancerous origin.

Retinoblastoma (Rb) is the most prevalent intraocular malignancy in children, with a worldwide survival rate <30%. We have developed a cancerous model of Rb in retinal organoids derived from genetically engineered human embryonic stem cells (hESCs) with a biallelic mutagenesis of the RB1 gene. These organoid Rbs exhibit properties highly consistent with Rb tumorigenesis, transcriptome, and genome-wide methylation. Single-cell sequencing analysis suggests that Rb originated from ARR3-positive maturing cone precursors during development, which was further validated by immunostaining. Notably, we found that the PI3K-Akt pathway was aberrantly deregulated and its activator spleen tyrosine kinase (SYK) was significantly up-regulated. In addition, SYK inhibitors led to remarkable cell apoptosis in cancerous organoids. In conclusion, we have established an organoid Rb model derived from genetically engineered hESCs in a dish that has enabled us to trace the cell of origin and to test novel candidate therapeutic agents for human Rb, shedding light on the development and therapeutics of other malignancies.

Towards stem cell-based neuronal regeneration for glaucoma.

Glaucoma is a neurodegenerative disease as a leading cause of global blindness. Retinal ganglion cell (RGC) apoptosis and optic nerve damage are the main pathological changes. Patients have elevated intraocular pressure and progressive visual field loss. Unfortunately, current treatments for glaucoma merely stay at delaying the disease progression. As a promising treatment, stem cell-based neuronal regeneration therapy holds potential for glaucoma, thereby great efforts have been paid on it. RGC regeneration and transplantation are key approaches for the future treatment of glaucoma. A line of studies have shown that a variety of cells can be used to regenerate RGCs, including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), and retinal progenitor cells (RPCs). In this review, we overview the current progress on the regeneration of pluripotent stem cell-derived RGCs and outlook the perspective and challenges in this field.