ABSTRACT
Chinese drug registration laws and regulations have always reserved a place for the new traditional Chinese medicine(TCM) drugs for syndromes, but so far no such new drugs have been approved for registration. This paper expounded on the relevant policies, regulations, and technologies of new TCM drugs for syndromes in China and pointed out that the application of the animal model of TCM syndromes to carry out pharmacodynamics research and clinical efficacy evaluation criteria of TCM syndromes were the main technical difficulties in the research and development of new TCM drugs for syndromes. Not all syndromes are suitable for developing new drugs, and the indications for new TCM drugs should be constant syndromes. Among the three research and development models of simple syndrome, syndrome-unified disease, and combined disease and syndrome, the research and development model of combined disease and syndrome is recommended. Clinical positioning is the key to new TCM drugs for syndromes. It is encouraged to conduct high-quality human use experience studies to determine the clinical positioning of new TCM drugs for syndromes, as well as the target population, dose, course of treatment, and initial therapeutic and safety, and apply for exemption from non-clinical effectiveness studies. Clinical trials of new TCM drugs for syndromes should take the target symptoms or signs as the main efficacy index and the efficacy of TCM syndromes as the secondary efficacy index. Clinical research program design should implement the "patient-centered" concept and introduce clinical outcome evaluation indicators. In the clinical safety evaluation, special conditions such as characteristic syndromes and changes should be considered. With the construction of the human use experience technology system and the promotion of the TCM registration and evaluation evidence system featuring the "combination of TCM theory, human use experience, and clinical trials", it is believed that many high-quality new TCM drugs for syndromes will be developed in the future.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , Research , Syndrome , China , Drugs, Chinese Herbal/therapeutic useABSTRACT
BACKGROUND: Stable angina pectoris (SAP) is a clinical condition characterized by reversible and temporary myocardial ischemia and hypoxia. A majority of SAP patients also experience depressive disorders, which adversely affect their disease prognosis and overall quality of life. However, the clinical utility of existing antidepressants is constrained by their side effects. Ginkgo biloba dropping pill (GBDP), a Chinese patented medication, has demonstrated efficacy in the treatment of both coronary heart disease and mental disorders. This prospective, randomized, double-blind, multicenter clinical trial aimed to assess the effectiveness and safety of GBDP as an adjuvant therapy for SAP complicated by depression. METHODS: Participants were randomly assigned in a 1:1 ratio to receive either GBDP or a placebo (5 pills, three times a day) in addition to standard therapy for a duration of 12 weeks. The Seattle Angina Questionnaire (SAQ) was administered every 4 weeks during the treatment, and angina event frequency was assessed weekly. The 36-item Short-Form (SF-36) and Hamilton Depression Scale (HAMD) scores were measured both before and after the treatment. RESULTS: Out of the 72 patients, 68 (n = 34 per group) completed the entire study. At the first visit (4 weeks ± 3 days), the SAQ-Angina Stability score in the GBDP group was significantly higher than that in the placebo group (p < 0.05). While the average weekly frequency of angina episodes in the placebo group notably increased after 12 weeks of treatment (p < 0.05), it displayed an improving trend in the GBDP group (p > 0.05). By the endpoint, each subcategory score of SF-36 in the GBDP group exhibited significant improvement compared to baseline (p < 0.05). The comparison of score improvement between the two groups revealed that the SF-PCS score of the GBDP group was higher than that of the placebo group (p < 0.05). HAMD scores in both groups significantly increased after treatment (p < 0.05). No discernible difference in the incidence of adverse reactions was observed between the two groups (p > 0.05). CONCLUSION: In patients with SAP complicated by depression, GBDP, when combined with standard treatment, rapidly and safely alleviates angina pectoris symptoms. It demonstrates therapeutic potential in enhancing the quality of life and alleviating depressive symptoms.
Subject(s)
Angina, Stable , Humans , Angina, Stable/drug therapy , Ginkgo biloba , Quality of Life , Prospective Studies , Depression , Double-Blind Method , Plant Extracts/adverse effects , Treatment OutcomeABSTRACT
Traditional Chinese medicine(TCM) preparations in medical institutions, as a unique and important form of preparations in China, have a long history of human use and serve as a bridge between clinical experience prescriptions and new Chinese medicine preparations. The state encourages medical institutions to transform their preparations into new traditional Chinese medicines, emphasizing their role as "incubators". Since the proposal of the traditional Chinese medicine registration and evaluation evidence system with the integration of TCM theory, human use experience(HUE), and clinical experience, the idea of transforming preparations used in medical institutions into new drugs based on HUE has been increasingly valued by drug research and development organizations. In the transformation process, pharmaceutical changes should be concerned from multiple aspects. This paper discusses the pharmaceutical changes and countermeasures based on the transformation of traditional Chinese medicine preparations in medical institutions into new drugs based on HUE from the aspects of excipients, dosage forms, production technology, production scale, packaging materials and containers, production sites, and registration standards. It is emphasized that scientific decisions should be made according to the characteristics and clinical needs of drugs to ensure the stability of drug quality. The impacts of pharmaceutical changes on drug quality should be objectively assessed based on appropriate evaluation indexes and detection methods. The layout should be carried out in advance, and the key pharmaceutical information of the preparations should be kept stable, so as to underpin the transformation of traditional Chinese medicine preparations in medical institutions into new drugs based on HUE.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , Drugs, Chinese Herbal/therapeutic use , Reference Standards , Quality Control , Drug Compounding , Pharmaceutical PreparationsABSTRACT
The human use experience of traditional Chinese medicine(TCM) is of great significance for the development of new traditional Chinese medicine. In 2023, the National Medical Products Administration(NMPA) issued the Special Regulations on Registration Management of Traditional Chinese Medicine, which explicitly encouraged the conduct of high-quality human use experience research on TCM clinical practice to obtain sufficient evidence for registration support. It also required that human use experience research should comply with relevant requirements and undergo registration verification. The quality of human use experience research on TCM directly determines the reliability of the evidence. This article discussed the quality requirements for human use experience research on TCM from the perspectives of basic requirements, organizational management, key pharmaceutical information, scientific research, risk management, ethical compliance, and study implementation and proposed differential treatment in quality requirements and registration verification focus based on different research purposes, stages, and types of studies. While ensuring the authenticity of data, retrospective studies should pay particular attention to the integrity of the data, and prospective studies should focus on the normativity of the data, which may affect the research conclusions. Human use experience research, as part of drug registration materials, falls within the scope of relevant regulatory oversight. Researchers should have a strong awareness of regulations to avoid serious quality issues. The standardized conduct of human use experience research on TCM requires joint efforts from regulatory authorities, applicants, research institutions, and researchers to establish a research quality management system based on the clinical characteristics of TCM.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , Prospective Studies , Reproducibility of Results , Retrospective Studies , Pharmaceutical Preparations , Drugs, Chinese Herbal/therapeutic useABSTRACT
Evidence-based medicine plays an important role in promoting the scientific nature of clinical decision-making. Howe-ver, there is a problem where evidence derived from clinical research may not necessarily be applicable to individual patients. Evidence-based medicine has been introduced into the field of traditional Chinese medicine(TCM) for over 20 years, and although certain achievements have been made, the overall level of clinical research evidence based on the principles of evidence-based medicine in TCM is not high. The acceptance of TCM diagnosis and treatment guidelines developed based on evidence-based medicine methods is generally low. As revealed by the analysis of the problems in the application of evidence-based medicine in the field of TCM, it is found that there is a structural contradiction between clinical randomized controlled trial(RCT) of TCM and the characteristics of TCM clinical practice. They cannot comprehensively, objectively, and truthfully reflect the clinical efficacy and safety of TCM. Conducting clinical RCTs of TCM in pursuit of "evidence" actually means giving up the advantages of TCM in clinical treatment based on syndrome differentiation, prescription changes along with syndromes, and treatment in accordance with three categories of disease cause, which leads to sacrificing some clinical effectiveness of TCM. Based on the concept of evidence-based medicine, this article proposed the construction of "clinical syndrome-based medicine" based on the optimal clinical experience, which was suitable for the characteristics of TCM clinical practice. The key to clinical syndrome-based medicine is the optimal clinical experience, and the core elements of the optimal clinical experience are regularity and reproducibility. Real-world research methods are recommended as a reference for obtaining the optimal clinical experience. Clinical syndrome-based medicine, combining the characteristics of TCM clinical practice and incorporating the concept of evidence-based medicine, is the product of integrating TCM into evidence-based medicine. It is dedicated to improving the clinical efficacy of TCM along with evidence-based medicine.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , Reproducibility of Results , Treatment Outcome , Evidence-Based Medicine , Syndrome , Drugs, Chinese Herbal/therapeutic useABSTRACT
BACKGROUND: Coronary heart disease(CHD) with stable angina pectoris is a common cardiovascular disease. It has been reported that 10%-81.4% of these patients suffer from psychological conditions,such as depression, which has been associated with more frequent angina, lower treatment satisfaction and lower perceived quality of life. Ginkgo biloba extract (GBE), the raw material of Ginkgo biloba dropping pills (GBDPs), is widely used to treat various conditions, including cardiovascular disease, ischaemic cerebrovascular disease, and depression. This clinical trial aimed to examine the efficacy and safety of GBDPs in improving the frequency of angina pectoris and the life quality of patients with stable angina pectoris and depression symptoms. METHODS: This randomised, double-blind, placebo-controlled, parallel-group and multicentre clinical trial will be conducted in four medical centres in China. We aim to recruit approximately 72 participants aged 18-75 years with depression and coronary heart disease with stable angina pectoris. Based on conventional drug treatment, participants will be randomly assignedto the treatment group (GBDPs group; n=36) or the control group (placebo group; n=36) at a 1:1 allocation ratio. After randomisation,follow-up will be done at 4 weeks, 8 weeks and 12 weeks (±3 days). Additionally, 30 healthy individuals will be enrolled to investigate the underlying pharmacological mechanisms of the effects of GBE. The primary outcomes will be the Seattle Angina Questionnaire score and the frequency of angina pectoris-related symptoms each week. The secondary outcomes will include the 36-item Short Form Health Survey quality-of-life scale, Hamilton Depression Scale and composite endpoint incidence of major adverse cardiovascular events. ETHICS AND DISSEMINATION: This trial has been approved by the Research Ethics Committee of the First Affiliated Hospital of Guangzhou University of Chinese Medicine, China (approval number: ZYYECK [2020]030). Written informed consent will be obtained from all participants. The results of this trial will be publicly shared through academic conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04529148 and ChiCTR2200066908.
Subject(s)
Angina, Stable , Coronary Disease , Drugs, Chinese Herbal , Humans , Angina, Stable/drug therapy , Ginkgo biloba , Drugs, Chinese Herbal/pharmacology , Control Groups , Depression/drug therapy , Quality of Life , Treatment Outcome , Double-Blind Method , Coronary Disease/complications , Coronary Disease/drug therapy , Randomized Controlled Trials as Topic , Multicenter Studies as TopicABSTRACT
Ethnic medicine has a rich history of application. Because of the large number of ethnic groups, wide geographical distribution, and unique medical systems in China, the research on the human use experience(HUE) of ethnic medicine should combine the characteristics of ethnic medicine, be based on practical experience, and respect folk practice and tradition. The clinical positioning of ethnic medicine should consider three factors, i.e., population region, dominant diseases, and clinical demand. We should consider the development of traditional preparations that meet the needs of ethnic regions and encourage the development of new drugs that can be popularized and used nationwide for the dominant diseases of ethnic medicines. Attention should be paid to the problems such as a large number of customary articles or substitutes of ethnic medicinal materials, the phenomena of foreign bodies with the same name and different names for the same substance, the different standards of medicinal materials, and the poor processing standards. The name, processing method, source, medicinal parts, and dosage of ethnic medicinal materials or decoction pieces should be determined, and resources should be carefully evaluated to ensure the safety of medicinal resources and ecology. The preparation of ethnic medicine is mostly in the form of pills, powder, ointment, etc., with simple processing technology. The problems of low-quality stan-dards of some preparations, different prescriptions with the same name, and inconsistent processing technology should be overcome, and the process route and main process parameters should be clarified to lay the foundation for the subsequent empirical research on HUE. In the collection and analysis of the HUE data of ethnic medicine, the core guiding ideology of "patient-centered" should be established, and the experience data of patients should be collected. The problems of weak links existing in the inheritance of ethnic medicine should be solved, and flexible and diverse methods should be adopted. Meanwhile, on the premise of complying with the requirements of the principles of medical ethics, we should respect the religion, culture, and customs of ethnic areas to obtain the key HUE information of ethnic medicine. On the basis of the patient preference information and differences in regional disease epidemiology, population characteristics, and medical practice, whether the HUE conclusions of ethnic medicine can be extrapolated to patients outside the region is evaluated from the aspects of clinical benefits, risk tolerance, risk acceptance, etc. The HUE research on ethnic medicine is carried out in a clear way to guide the research and development of new ethnic medicines.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , China , Reference Standards , Technology , Drugs, Chinese Herbal/therapeutic useABSTRACT
Human use experience(HUE) is important for the research and development of Chinese medicine. For the sake of more reliable data, the Professional Committee for Clinical Evaluation of Chinese Medicine of Chinese Pharmaceutical Association drafted the Expert Consensus on Human Use Experience Research of Traditional Chinese Medicine. It highlights that the research on HUE should have clear purposes, describe the theoretical basis of traditional Chinese medicine(TCM) for the clinical indications and prescriptions and the clinical value of prescriptions, especially the advantages or characteristics in clinical orientation and target population, evaluate the dosages and number of medicinals of prescriptions, verify the accordance with the preparation process of new Chinese medicine, analyze feasibility of the process for large-scale production and the rationality of the dosage form, and assess the medicinal material resources. Moreover, such research should have reasonable protocol and the collection of clinical data on HUE must comply with medical ethics and avoid conflicts of interest. The collection method should be selected depending on the characteristics of clinical data. Quality control measures should be formulated to ensure the authenticity, accuracy, completeness, reliability, and traceability of clinical data. The definitions on the clinical data should be uniform and clear, and methods should be adopted to avoid bias. The data can be statistically analyzed after the processing. Through the study of HUE, the clinical orientation, target population, commonly used dosage, course of treatment, preliminary efficacy and safety of Chinese medicine prescriptions will be clarified. On this basis, the data on the HUE should be discussed and conclusions will be drawn. Finally, a standardized report will be formed.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Consensus , Drug Prescriptions , Drugs, Chinese Herbal/therapeutic use , Humans , Reproducibility of ResultsABSTRACT
Application experience in humans, a summary of the clinical practice of traditional Chinese medicine(TCM), serves as an important data source for evaluating the safety, effectiveness, and clinical value of drugs in the development of new Chinese medicine. The collected data serving as the evaluation evidence through statistical analysis are critical to the research on the application experience in humans. This article summarized and analyzed the data characteristics and statistical methodology of application experience of Chinese medicine in humans, and concluded the data types, outcome evaluation, bias evaluation, confounding factors, and missing values. Furthermore, the article emphasized the importance of data analysis of application experience of Chinese medicine in humans for TCM evidence and put forward the current difficulties, such as low data quality and large internal bias, lack of individualized data processing methods, and lack of methods for "disease-syndrome combination" data. We believe that with the development of methodology, the application experience of Chinese medicine in humans can strongly support the development of new drugs in TCM.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Drugs, Chinese Herbal/therapeutic use , Humans , Research Design , SyndromeABSTRACT
Real world study(RWS) refers to the process of collecting real world data related to the health of research subjects in the real world environment for pre-set clinical problems and obtaining the status of drug use and potential benefits/risks through analysis. The data are derived from the hospital information system(HIS), medical insurance system, disease registration system, adverse drug reaction monitoring system, etc. Human use experience of traditional Chinese medicine(TCM) is a new concept put forward by experts after summarizing the problems existing in clinical trials of new TCM drugs. The data come partially from the real world, and more importantly, such key elements as the formulated prescriptions of new TCM drugs, principles and methods, and clinical applications should be covered. RWS is mainly used for adverse drug reaction monitoring after marketing, benefit evaluation of listed drugs, decision-making of medical treatment and medical insurance, as well as supervision and approval of special medical devices and special drugs. It is complementary to randomized controlled clinical trials. Human use experience is suitable for the research and development of Chinese medicinal compound preparations and the expansion of functions and indications. There are no special provisions for clinical indications and target population. There exists a sequential relationship between the human use experience and clinical trials. Specifi-cally, the summarization of human use experience provides good support for the design and implementation of clinical trials, which is an important segment in the research and development of new TCM drugs. The correlation between real-world data and research results and their reliability should be ensured in RWS, and the unreality should be avoided. The key to summarizing the human use experience is to identify the clinical orientation, target population, course of treatment, usage and dosage of new TCM drugs, and it should be noted that human use experience does not only mean clinical experience. Experimental clinical trial(PCT), a type of study in the real world, has been commonly employed for the summary of human use experience. RWS and human use experience are different research designs targeting different clinical questions in the research and development of new TCM drugs, which can be flexibly selected depending on the actual situation.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Drugs, Chinese Herbal/adverse effects , Humans , Prescriptions , Reproducibility of Results , ResearchABSTRACT
Collecting and summarizing human use experience(HUE) data, forming high-quality data and evidences that can be used for evaluation are the key links of HUE research on traditional Chinese medicine(TCM). The collection, collation and summary of human experience data were discussed in this paper. It is pointed out that the collection of HUE should be focus on the source of prescription of new traditional Chinese medicines, and be summarized based on dialectical thinking, experience in medication, characte-ristics of prescription and clinical application. The collected contents include prescription, process, clinical location and applicable population, efficacy data and safety data, etc. The methods include interview, clinical data summary and data mining. When the data formed based on HUE information is used as drug registration information, it is necessary to ensure that the data source is legal and compliant, and the ownership of intellectual property is clear.Data sources should meet the requirements of medical ethics. To avoid conflict of interest, data analysis should be conducted by an independent third party. It is necessary to develop the quality control measures of HUE data to ensure the data traceability, integrity, consistency and accuracy, and avoid data bias.The data of HUE should include the key data such as accurate clinical location and applicable population, recognized clinical efficacy and safety.After the formation of HUE, the statistical analysis plan of empirical data of human use should be formulated. Through strict data processing, statistical analysis and clinical interpretation, HUE can be produced for evaluation.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Data Collection , Humans , Prescriptions , Quality ControlABSTRACT
This article proposes that the research and development of new Chinese medicines should be based on the clinical values of traditional Chinese medicine(TCM), and expounds the multiple clinical values of new Chinese medicines such as therapeutic effects, adjuvant treatment effects, improvement of disease symptoms, improvement of quality of life, prevention of diseases, etc., so as to broaden the clinical indications of new Chinese medicines. It is pointed out that the clinical value of TCM determines the clinical efficacy evaluation method of new Chinese medicines, so as to construct a clinical evaluation system of new Chinese medicines with the characteristics of TCM. It is proposed that the clinical value of new Chinese medicines should be found under the guidance of TCM theo-ry and clinical practice, and the theoretical innovation of TCM should be emphasized. There is no difference in the clinical value of drugs, and the key is to meet the clinical needs of patients. The research and development of new Chinese medicines ignores the theoretical guidance of Chinese medicine, and relying solely on animal experiment data may lead to failure of clinical trials. Different from the individualized treatment of TCM clinical syndrome differentiation, summarizing the core pathogenesis of TCM is the basis for the development of new Chinese medicines. It is necessary to summarize the pathogenesis of the disease under the guidance of TCM theory and encourage the application of modern medical methods to clarify the diagnosis of the disease. In view of the characteristics of new Chinese medicine research and development, it is proposed that the supporting role of human experience should be emphasized, and the technical points of clinical trials of new syndrome-type Chinese medicines should be explained.The use of objective indicators for syndrome evaluation, the selection of appropriate scales, and the formulation of reasonable treatment courses are advocated. During the research and development of new Chinese medicines, it is not only necessary to pay attention to modern medical safety indicators, but also to observe the evolution of TCM syndromes and specific TCM symptoms.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Drugs, Chinese Herbal/therapeutic use , Humans , Quality of Life , Research , SyndromeABSTRACT
The relevant laws and regulations of drug clinical trials were introduced in this paper. It is pointed out that with drug re-gulatory laws and technological advances, clinical trials have become an important link in the development of new drugs of traditional Chinese medicines(TCM). Clinical trials of new drugs of TCM must comply with the requirement of "Good Clinical Practice for Trial on Medicinal Products". In view of the particularities of clinical trials of new drugs of TCM, China has established an ethical review system for clinical research in TCM and carried out ethical review and certification of TCM research. In order to guide the development of clinical trials of new drugs of TCM, relevant departments have promulgated a series of guidelines for clinical trials of it, and established a new review system and technical requirements for clinical trials. Since 1983, the "national clinical pharmacology base" has been established. At present, there are 96 drug clinical trial institutions and 32 phase I clinical research wards in TCM hospitals, which can meet the development of clinical trials of new drugs of TCM. In the long-term practice, the technical team has continued to grow and develop, the research experience and technical strength have been significantly improved, and a large number of experts have become the backbone of clinical research in Chinese medicine. It is pointed out that we should attach importance to risk and benefit assessment, human experience, select scientific, objective and appropriate effectiveness indexes, evaluate the efficacy of TCM syndromes, and encourage the use of electronic methods in clinical research of new drugs of TCM. Based on the analysis of clinical trials of TCM in recent five years, it is pointed out that the active degree of clinical trials of new drugs of TCM is not high, the innovation ability of it is insufficient and the ability and enthusiasm of all aspects need to be improved. It is of great significance to carry out clinical trials of new traditional Chinese medicines to upgrade the TCM industry and produce high-level evidence-based medicine evidences. The high quality development of TCM can be promoted by strengthening clinical trials of new drugs of TCM.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , China , Evidence-Based Medicine , Humans , SyndromeABSTRACT
Post-marketing evaluation of traditional Chinese medicine(TCM) is an important research stage in the life cycle of a drug, and the add-on-design is a common method for its post-marketing evaluation. This article introduces the basic concept of add-on-design, and points out that it is suitable for use based on the principles of medical ethics when the standard treatment should not be interrupted. The post-marketing evaluation of TCM should be carried out based on human experience and in compliance with regulations and ethics. The clinical values of TCM, such as the therapeutic effect for disease, improvement of disease symptoms, improvement in quality of life, as well as the synergism and toxicity attenuation of combined use of TCM and chemical drugs, should be fully reflected through the clinical trials designed with add-on-design. The key points of add-on-design are accurate clinical positioning, scientific estimation of sample size, and rigorous standard treatment. Standard treatment should be a recognized one, consistent and stable; appropriate and recognized efficacy indicators and targeted safety indicators should be selected; the design and operation of clinical research scheme should meet the requirements of randomization and blind method, with special emphasis on the production of qualified placebo. The add-on-design has the advantages that the rights and interests of the subjects are adequately protected. Besides, the research conclusions are easily put into clinical application. But there are also many difficulties, such as the influence of confounding bias, the "ceiling" effect of clinical efficacy, and the difficulty of interpretation of adverse events. Therefore, a rigorous research quality assu-rance system should be established, and the quality control of evaluation consistency of researchers should be emphasized to ensure strict quality control in the research process.
Subject(s)
Drugs, Chinese Herbal , Medicine, Chinese Traditional , Humans , Marketing , Quality Control , Quality of LifeABSTRACT
Low molecular weight (1.8 kDa) branched polyethylenimine (PEI) has been used as non-viral vector for gene delivery because of its low toxicity, however, its further application in biomedical field has been restricted due to its low gene transfection efficiency. Herein, ZnO microflowers were prepared to increase the gene expression level mediated by PEI. Four methods have been applied to tune the shape of ZnO microstructures. Scanning electron microscopy (SEM) demonstrated the successful preparation of four kinds of flower like ZnO microparticles. By loading PEI/pDNA into ZnO microparticles, the formed new complexes showed enhanced gene transfection compared to PEI/pDNA alone. Cell uptaking experiments explained a possible mechanism that the tips of ZnO microflowers penetrated into the surface of cells, thus facilitating the entry of gene cargo into cells. These findings highlight the potential of needle like microstructure as adjuvant for efficient biomacromolecular delivery.
Subject(s)
Gene Transfer Techniques , Metal Nanoparticles/chemistry , Polyethyleneimine/chemistry , Zinc Oxide/chemistry , Cell Death , Cell Survival , DNA/metabolism , Electrophoresis, Agar Gel , Endocytosis , HeLa Cells , Humans , Molecular Weight , Plasmids , Transfection , X-Ray DiffractionABSTRACT
Cationic liposomes have been widely used as efficient gene carriers. However, the serious cytotoxicity caused by exposed positive charges restricts the further application of those kinds of gene vectors. Thus, it is challenging to develop biocompatiable non-positive charge carriers to achieve high gene transfection efficiencies. Herein, we report a novel design by pasting biocompatible anionic polyelectrolyte, namely alginic acid, hyaluronic acid, pectin and polyglutamic acid, to the positive charge surface of liposome/pDNA complex. Through shielding the positive charges, the new gene carriers show decreased cytotoxicity while still maintaining high transfection efficiency. To be noted, the complex formed by coating polyglutamic acid to the surface of liposome/pDNA greatly enhanced the transfection efficiency in HepG2 cells, and the use of pectin shows increased transfection in MCF-7 cells. Hemolysis assay proved a possible mechanism that when the new gene complex was internalized into cells, as acidity increases, more side chains become hydrophobic, and thus destabilizing the endosomal membrane to accelerate DNA escape. The present results suggest that such anionic polyelectrolyte covered liposome based carrier possess promising application for clinical gene delivery.