Localized delivery of nanomedicine and antibodies for combating COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been a major health burden in the world. So far, many strategies have been investigated to control the spread of COVID-19, including social distancing, disinfection protocols, vaccines, and antiviral treatments. Despite the significant achievement, due to the constantly emerging new variants, COVID-19 is still a great challenge to the global healthcare system. It is an urgent demand for the development of new therapeutics and technologies for containing the wild spread of SARS-CoV-2. Inhaled administration is useful for the treatment of lung and respiratory diseases, and enables the drugs to reach the site of action directly with benefits of decreased dose, improved safety, and enhanced patient compliance. Nanotechnology has been extensively applied in the prevention and treatment of COVID-19. In this review, the inhaled nanomedicines and antibodies, as well as intranasal nanodrugs, for the prevention and treatment of COVID-19 are summarized.

Neutralization of SARS-CoV-2 pseudovirus using ACE2-engineered extracellular vesicles

The spread of coronavirus disease 2019 (COVID-19) throughout the world has resulted in stressful healthcare burdens and global health crises. Developing an effective measure to protect people from infection is an urgent need. The blockage of interaction between angiotensin-converting enzyme 2 (ACE2) and S protein is considered an essential target for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drugs. A full-length ACE2 protein could be a potential drug to block early entry of SARS-CoV-2 into host cells. In this study, a therapeutic strategy was developed by using extracellular vesicles (EVs) with decoy receptor ACE2 for neutralization of SARS-CoV-2. The EVs embedded with engineered ACE2 (EVs-ACE2) were prepared; the EVs-ACE2 were derived from an engineered cell line with stable ACE2 expression. The potential effect of the EVs-ACE2 on anti-SARS-CoV-2 was demonstrated by both in vitro and in vivo neutralization experiments using the pseudovirus with the S protein (S-pseudovirus). EVs-ACE2 can inhibit the infection of S-pseudovirus in various cells, and importantly, the mice treated with intranasal administration of EVs-ACE2 can suppress the entry of S-pseudovirus into the mucosal epithelium. Therefore, the intranasal EVs-ACE2 could be a preventive medicine to protect from SARS-CoV-2 infection. This EVs-based strategy offers a potential route to COVID-19 drug development.

Inhaled heparin polysaccharide nanodecoy against SARS-CoV-2 and variants

The heparin polysaccharide nanoparticles block the interaction between heparan sulfate/S protein and inhibit the infection of both wild-type SARS-CoV-2 pseudovirus and the mutated strains through pulmonary delivery.Image 1.

Genetically-engineered "all-in-one" vaccine platform for cancer immunotherapy

An essential step for cancer vaccination is to break the immunosuppression and elicit a tumor-specific immunity. A major hurdle against cancer therapeutic vaccination is the insufficient immune stimulation of the cancer vaccines and lack of a safe and efficient adjuvant for human use. We discovered a novel cancer immunostimulant, trichosanthin (TCS), that is a clinically used protein drug in China, and developed a well-adaptable protein-engineering method for making recombinant protein vaccines by fusion of an antigenic peptide, TCS, and a cell-penetrating peptide (CPP), termed an "all-in-one" vaccine, for transcutaneous cancer immunization. The TCS adjuvant effect on antigen presentation was investigated and the antitumor immunity of the vaccines was investigated using the different tumor models. The vaccines were prepared

Recent progress in drug delivery

Drug delivery systems (DDS) are defined as methods by which drugs are delivered to desired tissues, organs, cells and subcellular organs for drug release and absorption through a variety of drug carriers. Its usual purpose to improve the pharmacological activities of therapeutic drugs and to overcome problems such as limited solubility, drug aggregation, low bioavailability, poor biodistribution, lack of selectivity, or to reduce the side effects of therapeutic drugs. During 2015-2018, significant progress in the research on drug delivery systems has been achieved along with advances in related fields, such as pharmaceutical sciences, material sciences and biomedical sciences. This review provides a concise overview of current progress in this research area through its focus on the delivery strategies, construction techniques and specific examples. It is a valuable reference for pharmaceutical scientists who want to learn more about the design of drug delivery systems.

Tat-functionalized Ag-FeO nano-composites as tissue-penetrating vehicles for tumor magnetic targeting and drug delivery

In this paper, we prepared a dual functional system based on dextrin-coated silver nanoparticles which were further attached with iron oxide nanoparticles and cell penetrating peptide (Tat), producing Tat-modified Ag-FeO nanocomposites (Tat-FeAgNPs). To load drugs, an -SH containing linker, 3-mercaptopropanohydrazide, was designed and synthesized. It enabled the silver carriers to load and release doxorubicin (Dox) in a pH-sensitive pattern. The delivery efficiency of this system was assessed using MCF-7 cells, and using null BalB/c mice bearing MCF-7 xenograft tumors. Our results demonstrated that both Tat and externally applied magnetic field could promote cellular uptake and consequently the cytotoxicity of doxorubicin-loaded nanoparticles, with the IC of Tat-FeAgNP-Dox to be 0.63 µmol/L. The delivery efficiency of Tat-FeAgNP carrying Cy5 to the mouse tumor was analyzed using the optical imaging tests, in which Tat-FeAgNP-Cy5 yielded the most efficient accumulation in the tumor (6.7±2.4% ID of Tat-FeAgNPs). Anti-tumor assessment also demonstrated that Tat-FeAgNP-Dox displayed the most significant tumor-inhibiting effects and reduced the specific growth rate of tumor by 29.6% ( = 0.009), which could be attributed to its superior performance in tumor drug delivery in comparison with the control nanovehicles.

Biomimetic albumin-modified gold nanorods for photothermo-chemotherapy and macrophage polarization modulation

Nanotechnology-based photothermal therapy has attracted great attention in the past decade. Nevertheless, photothermal therapy has some inherent drawbacks, such as the uneven heat production and limited laser penetration, often leading to insufficient treatment outcomes. Here, we developed a combination strategy to improve cancer therapy. The biomimetic albumin-modified gold nanorods (AuNRs) were prepared with incorporation of paclitaxel (PTX). This therapeutic system was characterized by several features. First, the albumin modification enhanced the biocompatibility and colloidal stability. Second, the surface-coated albumin promoted cellular uptake the albumin-binding protein pathway. Third, PTX was incorporated hydrophobic interaction between PTX and the albumin lipophilic domain. Fourth, the system can be used for combined photothermo-chemotherapy for yielding synergistic effects. The antitumor activity of the system was evaluated both and using the HCT116 colon cancer cell and tumor model. The combination therapy was found with an enhanced treatment efficiency and no obvious side effect. Most importantly, the thermal effect was also discovered with the ability to modulate the tumor microenvironments and suppress the macrophages polarization towards the M2 pro-tumor phenotype. It could be a mechanism for photothermal immunotherapy. The combination strategy and the system provide a potential method for cancer therapy.

Improved method for synthesis of low molecular weight protamine-siRNA conjugate

RNAi technology has aroused wide public interest due to its high efficiency and specificity to treat multiple types of diseases. However, the effective delivery of siRNA remains a challenge due to its large molecular weight and strong anionic charge. Considering their remarkable functions and features that are often desired in drug delivery carriers, biomimetic systems for siRNA delivery become an effective and promising strategy. Based on this, covalent attachment of synthetic cell penetrating peptides (CPP) to siRNA has become of great interest. We developed a monomeric covalent conjugate of low molecular weight protamine (LMWP, a well-established CPP) and siRNA a cytosol-cleavable disulfide linkage using PEG as a crosslinker. Results showed that the conjugates didn't generate coagulation, and exhibited much better RNAi potency and intracellular delivery compared with the conventional charge-complexed CPP/siRNA aggregates. Three different synthetic and purification methods were compared in order to optimize synthesis efficiency and product yield. The methodology using hetero-bifunctional NHS-PEG-OPSS as a crosslinker to synthesize LMWP-siRNA simplified the synthesis and purification process and produced the highest yield. These results pave the way towards siRNA biomimetic delivery and future clinical translation.

Nose-to-brain delivery of macromolecules mediated by cell-penetrating peptides

Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood-brain barrier (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to circumventing the BBB and has already been intensively investigated for brain delivery of small drugs, new challenges arise for intranasal delivery of proteins because of their larger size and hydrophilicity. In order to overcome the barriers and take advantage of available pathways (e.g., epithelial tight junctions, uptake by olfactory neurons, transport into brain tissues, and intra-brain diffusion), a low molecular weight protamine (LMWP) cell-penetrating peptide was utilized to facilitate nose-to-brain transport. Cell-penetrating peptides (CPP) have been widely used to mediate macromolecular delivery through many kinds of biobarriers. Our results show that conjugates of LMWP-proteins are able to effectively penetrate into the brain after intranasal administration. The CPP-based intranasal method highlights a promising solution for protein therapy of brain diseases.

Reversal of Multidrug Resistance of Human Colon Cancer Cells by Dihydroartemisin / 广州中医药大学学报

Objective To investigate the multidrug-resistance reversal action and mechanism of dihydroartemisin (DHA) on human colon cancer cell line HCT8/ADR. Methods The cytotoxicity of dihydroartemisin combined with doxorubicin(DOX) was determined by methyl thiazolyl tetrazolium(MTT) assay and cell apoptosis was observed by flow cytometry. Western blot assay was used to measure the autophagy. Results The combined treatment with dihydroartemisin and doxorubicin significantly enhanced the cytotoxicity in HCT8/ADR cells and effectively increased the apoptotic level. Autophagy was also induced by the combined treatment , which maybe played a crucial role in the regulation of doxorubicin-sensitization of HCT8/ADR cells. Conclusion The results indicated that dihydroartemisin can reverse multidrug resistance through increasing the doxorubicin-sensitivity of HCT8/ADR cells.

Study on Anti-tumor Activities of Trichosanthin Mediated by Low Molecular Weight Protamine / 广州中医药大学学报

Objective To investigate the anti-tumor activities of cell-penetrating peptide ( CPP) - mediated trichosanthin ( TCS) , which is a recombinant protein obtained from Radix Trichosanthis. Methods Cysteine residue was introduced to the C-terminus of TCS by protein recombinant technique, and then with the newly-formed terminal as the modification site, TCS was coupled with CPP. As a target protein, CPP-mediated TCS was isolated and purified by affinity chromatography. The expression of the target protein and its responsiveness to reducing substances were detected by using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The cellular uptake rate of CPP-mediated TCS was determined by using cell uptake test, and its anti-tumor activity was measured by using methyl thiazolyl tetrazolium (MTT) assay. Results The TCS-CPP compound had been successfully developed in this study, and showed certain reducing responsiveness. After modified with CPP, TCS had higher cellular uptake rate and stronger anti-tumor effect on HeLa and MCF-7 cells. Conclusion TCS modified by CPP can enhance the anti-tumor activities of TCS.

Cell-penetrating chimeric apoptotic peptide AVPI-LMWP/DNA co-delivery system for cancer therapy / 药学学报

To develop a cell-penetrating chimeric apoptotic peptide AVPI-LMWP/DNA co-delivery system for cancer therapy, we prepared the AVPI-LMWP/pTRAIL self-assembled complexes containing a therapeutic combination of peptide drug AVPI and DNA drug TRAIL. The chimeric apoptotic peptide AVPI-LMWP was synthesized using the standard solid-phase synthesis. The cationic AVPI-LMWP could condense pTRAIL by electrostatic interaction. The physical-chemical properties of the AVPI-LMWP/pTRAIL complexes were characterized. The cellular uptake efficiency and the inhibitory activity of the AVPI-LMWP/pTRAIL complexes on tumor cell were also performed. The results showed that the AVPI-LMWP/pTRAIL complexes were successfully prepared by co-incubation. With the increase of mass ratio (AVPI-LMWP/DNA), the particle size was decreased and the zeta potential had few change. Agarose gel electrophoresis showed that AVPI-LMWP could fully bind and condense pTRAIL at a mass ratio above 15:1. Cellular uptake efficiency was improved along with the increased ratio of W(AVPI-LMWP)/WpTRAIL. The in vitro cytotoxicity experiments demonstrated that the AVPI-LMWP/pTRAIL (W:W = 20:1) complexes was significantly more effective than the pTRAIL, AVPI-LMWP alone or LMWP/pTRAIL complexes on inhibition of HeLa cell growth. Our studies indicated that the AVPI-LMWP/pTRAIL co-delivery system could deliver plasmid into HeLa cell and induce tumor cell apoptosis efficiently, which showed its potential in cancer therapy using combination of apoptoic peptide and gene drugs.

Assay of Ginsenoside Rg_1 and Rb_1 and Notoginsenoside R_1 in Radix Notoginseng by HPLC/ELSD with Solid Phase Extraction / 中药新药与临床药理

Objective To establish a method for determinin g the content of ginsenoside Rg 1 and Rb 1 and notoginsenoside R 1 in Radix Notoginseng.Methods HPLC /ELSD with solid phase extraction(SPE)was applied.The chromatographic conditions were:Hypersil amino -column (200mm ?4.0mm,5?m),acetonitrile -isopropanol -ammon ium acetate(75∶20∶5;acetic acid adjusted pH to5.0)as mobile phrase,flow rate at 0.6mL?min -1 ,column temperature at room temperature,ELSD nebulization at 55℃and flow rate of nitrogen at 2.3L?min -1 Results The linear range of ginseno-side Rg 1 and Rb 1 ,notoginsenoside R 1 was from 1.0to 10.0?g .The average recoveries were 95.5%～102.5%.The inter -day RSD and intra -day were less than 2%and 4%respectively.Conclusion The method is simple and accu-rate,and can be used for the quality contro l of Radix Notoginseng and its preparations.

Assay of The Contents of Ginsenoside Rg_1 and Rb_1, Notoginsenoside R_1 in Compound Danshen Dropping Pill by HPLC/ELSD / 中药新药与临床药理

Objective: To establish a method for determining the contents of ginsenoside Rg1 and Rb1, notoginsenoside Rg1 in compound Danshen dropping pill by HPLC/ELSD. Methods: Ginsenoside Rg1 and Rb1, notoginsenoside R1 were pretreated with solid phase extraction(SPE). The extraction conditions were as follow: Hypersit NH2 column, acetonitrile-isopropanol-10mmol/L ammonium acetate( 15∶4∶1 ) as mobile phase (iced acetic acid adjusting pH as 5.0) and the flow rate at 0.6 mL/min. Results: The linear range was from 1.0 to 10.0?g for ginsenoside Rg1 and Rb1, and notoginsenoside Rg1. The average recovery was 95.3%～100.4%.The inter-day RSD and intra-day RSD were less than 2%and 4%respectively. Conclusion: The method is concise and accurate, and will be helpful for the quality control of Radix Notoginseng and its preparations.