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Xuan Pan,1,* Ting Han,2,* Zixuan Zhao,3,4 Xiaoming Wang,1 Xiaosan Fang1 1Department of Hepato-Biliary-Pancreatic Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, 241000, People’s Republic of China; 2Department of Gastroenterology, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, 241000, People’s Republic of China; 3The Translational Research Institute for Neurological Disorders of Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, 241000, People’s Republic of China; 4The Institute of Brain Science, Wannan Medical College, Wuhu, 241000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiaosan Fang; Xiaoming Wang, Department of Hepato-Biliary-Pancreatic Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), 2 West Zheshan Road, Wuhu, 241002, People’s Republic of China, Tel +86-0553-5739219, Email 20142031@wnmc.edu.cn; wxm6901@126.comAbstract: The high malignant degree and poor prognosis of pancreatic cancer (PC) pose severe challenges to the basic research and clinical translation of next-generation therapies. The rise of immunotherapy has improved the treatment of a variety of solid tumors, while the application in PC is highly restricted by the challenge of immunosuppressive tumor microenvironment. The latest progress of nanotechnology as drug delivery platform and immune adjuvant has improved drug delivery in a variety of disease backgrounds and enhanced tumor therapy based on immunotherapy. Based on the immune loop of PC and the status quo of clinical immunotherapy of tumors, this article discussed and critically analyzed the key transformation difficulties of immunotherapy adaptation to the treatment of PC, and then proposed the rational design strategies of new nanocarriers for drug delivery and immune regulation, especially the design of combined immunotherapy. This review also put forward prospective views on future research directions, so as to provide information for the new means of clinical treatment of PC combined with the next generation of nanotechnology and immunotherapy. Keywords: pancreatic cancer, immunotherapy, nanomedicine, immunosuppressive tumor microenvironment regulation, combined drug delivery strategy

Yujie Wang,1 Tingting Deng,1 Xi Liu,2 Xueyang Fang,1 Yongpan Mo,3 Ni Xie,4 Guohui Nie,1 Bin Zhang,1 Xiaoqin Fan1,4 1Shenzhen Key Laboratory of Nanozymes and Translational Cancer Research, Department of Otolaryngology, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, 518035, People’s Republic of China; 2Department of Nephrology, Shenzhen Longgang Central Hospital, Shenzhen, 518116, People’s Republic of China; 3Department of Breast Surgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, 518035, People’s Republic of China; 4The Bio-Bank of Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, Guangdong, 518035, People’s Republic of ChinaCorrespondence: Bin Zhang; Xiaoqin Fan, Email binzhang@email.szu.edu.cn; fanxiaoqin83@163.comAbstract: The tumor microenvironment (TME) is a complex and dynamic entity, comprising stromal cells, immune cells, blood vessels and extracellular matrix, which is intimately associated with the occurrence and development of cancers, as well as their therapy. Utilizing the shared characteristics of tumors, such as an acidic environment, enzymes and hypoxia, researchers have developed a promising cancer therapy strategy known as responsive release of nano-loaded drugs, specifically targeted at tumor tissues or cells. In this comprehensive review, we provide an in-depth overview of the current fundamentals and state-of-the-art intelligent strategies of TME-responsive nanoplatforms, which include acidic pH, high GSH levels, high-level adenosine triphosphate, overexpressed enzymes, hypoxia and reductive environment. Additionally, we showcase the latest advancements in TME-responsive nanoparticles. In conclusion, we thoroughly examine the immediate challenges and prospects of TME-responsive nanopharmaceuticals, with the expectation that the progress of these targeted nanoformulations will enable the exploitation, overcoming or modulation of the TME, ultimately leading to significantly more effective cancer therapy. Keywords: tumor microenvironment, stimulus-responsive, drug delivery, cancer therapy, intelligent biomedicine

Longmin Chen,1 Qing Zhou,2 Xun Fang,1 Qianqian Xu,2 Yuan Zou,2 Jing Zhang2 1Department of Rheumatology and Immunology, the Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China; 2Department of Respiratory and Critical Care Medicine, NHC Key Laboratory of Respiratory Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of ChinaCorrespondence: Jing Zhang, Department of Respiratory and Critical Care Medicine, NHC Key Laboratory of Respiratory Disease, Tongji Hospital Research Building, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Caidian, 430100, People’s Republic of China, Email jingzhang@tjh.tjmu.edu.cnBackground: Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease characterized by synovial inflammation and joint destruction. Despite progress in RA therapy, it remains difficult to achieve long-term remission in RA patients. Phosphodiesterase 3B (Pde3b) is a member of the phosphohydrolyase family that are involved in many signal transduction pathways. However, its role in RA is yet to be fully addressed.Methods: Studies were conducted in arthritic DBA/1 mice, a suitable mouse strain for collagen-induced rheumatoid arthritis (CIA), to dissect the role of Pde3b in RA pathogenesis. Next, RNAi-based therapy with Pde3b siRNA-loaded liposomes was assessed in a CIA model. To study the mechanism involved, we investigated the effect of Pde3b knockdown on macrophage polarization and related signaling pathway.Results: We demonstrated that mice with CIA exhibited upregulated Pde3b expression in macrophages. Notably, intravenous administration of liposomes loaded with Pde3b siRNA promoted the macrophage anti-inflammatory program and alleviated CIA in mice, as indicated by the reduced inflammatory response, synoviocyte infiltration, and bone and cartilage erosion. Mechanistic study revealed that depletion of Pde3b increased cAMP levels, by which it enhanced PKA-CREB-C/EBPβ pathway to transcribe the expression of anti-inflammatory program-related genes.Conclusion: Our results support that Pde3b is involved in the pathogenesis of RA, and Pde3b siRNA-loaded liposomes might serve as a promising therapeutic approach against RA.Keywords: rheumatoid arthritis, Pde3b, liposomes, macrophages

Chenxi Li,1,2,* Xueyang Fang,1,* Han Zhang,1,3 Bin Zhang1 1Shenzhen Key Laboratory of Nanozymes and Translational Cancer Research, Institute of Translational Medicine Department of Otolaryngology Shenzhen Second People’s Hospital, the First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, 518035, People’s Republic of China; 2Graduate Collaborative Training Base of Shenzhen Second People’s Hospital, Heng Yang Medical School, University of South China, Hengyang, Hunan, 421001, People’s Republic of China; 3International Collaborative Laboratory of 2D, Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, People’s Republic of China*These authors contributed equally to this workCorrespondence: Bin Zhang; Xueyang Fang, Email binzhang@email.szu.edu.cn; FANGXueyang0210@163.comAbstract: In recent years, metal-containing two-dimensional (2D) nanomaterials, among various 2D nanomaterials have attracted widespread attention because of their unique physical and chemical properties, especially in the fields of biomedical applications. Firstly, the review provides a brief introduction to two types of metal-containing 2D nanomaterials, based on whether metal species take up the major skeleton of the 2D nanomaterials. After this, the synthetical approaches are summarized, focusing on two strategies similar to other 2D nanomaterials, top-down and bottom-up methods. Then, the performance and evaluation of these 2D nanomaterials when applied to cancer therapy are discussed in detail. The specificity of metal-containing 2D nanomaterials in physics and optics makes them capable of killing cancer cells in a variety of ways, such as photodynamic therapy, photothermal therapy, sonodynamic therapy, chemodynamic therapy and so on. Besides, the integrated platform of diagnosis and treatment and the clinical translatability through metal-containing 2D nanomaterials is also introduced in this review. In the summary and perspective section, advanced rational design, challenges and promising clinical contributions to cancer therapy of these emerging metal-containing 2D nanomaterials are discussed. Keywords: metal-containing two-dimensional nanomaterials, nanotechnology-based therapy, cancer precision treatment, theranostic platform

Jia Zeng,1 Peng Sun,1 Xinning Fang,1 Yicheng Jiang,1 Zhenghong Wu,1 Xiaole Qi1,2 1Key Laboratory of Modern Chinese Medicines, China Pharmaceutical University, Nanjing, People’s Republic of China; 2Industrial Technology Innovation Platform, Zhejiang Center for Safety Study of Drug Substances, Hangzhou, People’s Republic of ChinaCorrespondence: Zhenghong Wu; Xiaole Qi, Key Laboratory of Modern Chinese Medicines, China Pharmaceutical University, No. 639 Longmian Road, Jiangning District, Nanjing City, Jiangsu Province, 210009, People’s Republic of China, Tel +86 15062208341 ; +86 25 83179703, Email zhenghongwu66@cpu.edu.cn; qixiaole523@cpu.edu.cnBackground: Synergistic chemotherapy has been proved as an effective antitumor means in clinical practice. However, most co-administration treatment often lacks simultaneous control over the release of different chemotherapeutic agents.Materials and Methods: β-cyclodextrin modified hyaluronic acid was the “shell”, and the oxidized ferrocene-stearyl alcohol micelles served as the “core”, where doxorubicin (DOX) and curcumin (CUR) were loaded in shell and core of the bilayer nanoparticles (BNs), respectively. The pH- and glutathione (GSH)-responsive synchronized release behavior was evaluated in different mediums, and the in vitro and in vivo synergistic antitumor effect and CD44-mediated tumor targeting efficiency were further investigated.Results: These BNs had a spherical structure with the particle size of 299 ± 15.17 nm, while the synchronized release behaviour of those two drugs was proved in the medium with the pH value of 5.5 and 20 mM GSH. The co-delivery of DOX and CUR reduced the IC50 value by 21% compared to DOX alone, with a further 54% reduction after these BNs delivery measurements. In tumor-bearing mouse models, these drug-loaded BNs showed significant tumor targeting, enhanced antitumor activity and reduced systemic toxicity.Conclusion: The designed bilayer nanoparticle could be considered as potential chemotherapeutic co-delivery platform for efficient synchronized microenvironment respond and drug release. Furthermore, the simultaneous and synergistic drug release guaranteed the enhanced antitumor effects during the co-administration treatment.Graphical Abstract: Keywords: tumor microenvironment, combination chemotherapy, pH- and GSH-responsive, tumor targeting

Dingli Xu,1,2,* Kaifeng Gan,3,* Yang Wang,1 Zeting Wu,1 Yulong Wang,1 Song Zhang,1 Yujie Peng,2 Xuguang Fang,4 Hua Wei,5 Yansheng Zhang,5 Weihu Ma,2 Jing Chen5 1The Affiliated Hospital of Ningbo University Medical School, Ningbo, 315000, People’s Republic of China; 2Ningbo No.6 Hospital, Ningbo, 315000, People’s Republic of China; 3The Affiliated Lihuili Hospital of Ningbo University, Ningbo, 31500, People’s Republic of China; 4The First Affiliated Hospital of Xi ‘an Medical University, Xi’an, 710082, People’s Republic of China; 5Zhejiang International Scientific and Technological Cooperative Base of Biomedical Materials and Technology, Zhejiang Engineering Research Center for Biomedical Materials, Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315300, People’s Republic of China*These authors contributed equally to this workCorrespondence: Weihu Ma; Jing Chen, Email 944973034@qq.com; jing.chen@nimte.ac.cnIntroduction: Bone delay union is mostly caused by lack of blood supply. Although autografts, allografts and artificial bone have been widely used to treat bone delay union, the bone regeneration fails in the ischemic site accompanied by the bone donor site complications and disease transmission. Recently, there is a growing recognition of the importance of hydrogel scaffolds which are regarded as an eligible engineer tissue for bone repair. However, hydrogel is still limited in improving neovascularization.Methods: In this work, black phosphorus nanosheet and deferoxamine (BPN-DFO) were loaded in the gelatin hydrogel to overcome the high risk of bone delay union and systemically investigated the regeneration capability of BPN-DFO hydrogel in vitro and vivo.Results: The resulting BPN-DFO hydrogel scaffold showed superior swollen, degradation and release rate, as well as satisfied biocompatibility. BPN-DFO hydrogel shown the significant up-expression of mRNA related to bone regeneration and cell proliferation. In vivo, the proposed BPN-DFO hydrogel significantly improved osteogenesis and neovascularization in the ischemic tibial bone site of SD rats with acute femoral artery occlusion. Both macroscopic and histological evaluation of new regenerated bone showed newly formed blood vessel and collagen using BPN-DFO hydrogel. The immunohistochemistry and RT-PCR revealed that the bone regeneration could be improved via BMP/Runx2 pathway.Conclusion: The BPN-DFO hydrogel possesses potential tissue engineer material for ischemic bone defect treatment. However, furthermore studies are needed to testify the safety and efficacy of BPN-DFO hydrogel.Keywords: ischemic bone defect regeneration, hydrogel scaffolds, black phosphorus nanosheets, deferoxamine

Chen Y, Zhang W, Huang Y, et al. Int J Nanomedicine. 2015;10:4043-4057. The Editor and Publisher of the International Journal of Nanomedicine wish to retract the published article. Concerns were raised regarding the alleged duplication of an image in Figure 10 with the same image from Figure 8B in Huang et al, 2016 ‘c(RGDyK)-decorated Pluronic micelles for enhanced doxorubicin and paclitaxel delivery to brain glioma’ (https://doi.org/10.2147/IJN.S104162). Specifically, Figure 10, Heart, F127/P105/MTX appears to have been duplicated with the same image from Figure 8B, Heart, Saline in Huang et al, 2016. The authors responded to our queries and explained that the animal experimental work for both studies was performed at the same time. It was possible an error was made during the arrangement of the H&E images for the respective figures from both articles. However, given the length of time that has passed since the completion of these studies the authors were no longer able to retrieve the original data. To help maintain the integrity of the scientific record the authors agreed with the decision to retract the article. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”.

Huang Y, Liu W, Gao F, Fang X, Chen Y. Int J Nanomedicine. 2016;11:1629–1641. The Editor and Publisher of the International Journal of Nanomedicine wish to retract the published article. Concerns were raised regarding the alleged duplication of an image in Figure 8B with the same image from Figure 10 in Chen et al, 2015 ‘The therapeutic effect of methotrexate-conjugated Pluronic-based polymeric micelles on the folate receptor-rich tumors treatment’ (https://doi.org/10.2147/IJN.S79045). Figure 8B, Heart, Saline appears to have been duplicated with the same image from Figure 10, Heart, F127/P105/MTX in Chen et al, 2015. The authors responded to our queries and explained that the animal experimental work for both studies was performed at the same time. It was possible an error was made during the arrangement of the H&E images for the respective figures from both articles. However, given the length of time that has passed since the completion of these studies the authors were no longer able to retrieve the original data. To help maintain the integrity of the scientific record the authors agreed with the decision to retract the article. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”.

Wenbing Wan,1–3,* Shiwen Zhang,2–4,* Liangpeng Ge,2,3,5 Qingtao Li,1 Xingxing Fang,1 Quan Yuan,4 Wen Zhong,6 Jun Ouyang,1 Malcolm Xing1,2,7 1Department of Anatomy, Guangdong Provincial Medical Biomechanical Key Laboratory, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Mechanical Engineering, University of Manitoba, Winnipeg, MB, Canada; 3Manitoba Institute of Child Health, Winnipeg, MB, Canada; 4Sichuan University, Chengdu, People’s Republic of China; 5Chongqing Academy of Animal Sciences, Chongqing, People’s Republic of China; 6Department of Textile Sciences, University of Manitoba, Winnipeg, MB, Canada; 7Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada *These authors contributed equally to this work Abstract: Bone tissue engineering through seeding of stem cells in three-dimensional scaffolds has greatly improved bone regeneration technology, which historically has been a constant challenge. In this study, we researched the use of adipose-derived stem cell (ADSC)-laden layer-by-layer paper-stacking polycaprolactone/gelatin electrospinning nanofibrous membranes for bone regeneration. Using this novel paper-stacking method makes oxygen distribution, nutrition, and waste transportation work more efficiently. ADSCs can also secrete multiple growth factors required for osteogenesis. After the characterization of ADSC surface markers CD29, CD90, and CD49d using flow cytometry, we seeded ADSCs on the membranes and found cells differentiated, with significant expression of the osteogenic-related proteins osteopontin, osteocalcin, and osteoprotegerin. During 4 weeks in vitro, the ADSCs cultured on the paper-stacking membranes in the osteogenic medium exhibited the highest osteogenic-related gene expressions. In vivo, the paper-stacking scaffolds were implanted into the rat calvarial defects (5 mm diameter, one defect per parietal bone) for 12 weeks. Investigating with microcomputer tomography, the ADSC-laden paper-stacking membranes showed the most significant bone reconstruction, and from a morphological perspective, this group occupied 90% of the surface area of the defect, produced the highest bone regeneration volume, and showed the highest bone mineral density of 823.06 mg/cm3. From hematoxylin and eosin and Masson staining, the new bone tissue was most evident in the ADSC-laden scaffold group. Using quantitative polymerase chain reaction analysis from collected tissues, we found that the ADSC-laden paper-stacking membrane group presented the highest osteogenic-related gene expressions of osteocalcin, osteopontin, osteoprotegerin, bone sialoprotein, runt-related transcription factor 2, and osterix (two to three times higher than the control group, and 1.5 times higher than the paper-stacking membrane group in all the genes). It is proposed that ADSC-laden layer-by-layer paper-stacking scaffolds could be used as a way of promoting bone defect treatment. Keywords: paper-stacking, layer-by-layer membrane, bone regeneration, adipose-derived stem cells, calvarial defect

With many desirable features, such as being more effective and having multiple effects, antiangiogenesis has become one of the promising cancer treatments. The aim of this study was to design and synthesize a new targeted bioresponsive nanosystem with antiangiogenesis properties. The mUPR@Ru(POP) nanosystem was constructed by the polymerization of Ulva lactuca polysaccharide and N -isopropyl acrylamide, decorated with methoxy polyethylene glycol and Arg-Gly-Asp peptide, and encapsulated with anticancer complex [Ru(phen)2p-MOPIP](PF 6 ) 2 ·2H 2 O. The nanosystem was both pH responsive and targeted. Therefore, the cellular uptake of the drug was greatly improved. Moreover, the mUPR@Ru(POP) had strong suppressive effects against vascular endothelial growth factor (VEGF)-induced angiogenesis through apoptosis. The mUPR@Ru(POP) significantly inhibited VEGF-induced human umbilical vein endothelial cell migration, invasion, and tube formation. These findings have presented new insights into the development of antiangiogenesis drugs., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Brain glioma therapy is an important challenge in oncology. Here, doxorubicin (DOX) and paclitaxel (PTX)-loaded cyclic arginine-glycine-aspartic acid peptide (c(RGDyK))-decorated Pluronic micelles (cyclic arginine-glycine-aspartic acid peptide-decorated Pluronic micelles loaded with doxorubicin and paclitaxel [RGD-PF-DP]) were designed as a potential targeted delivery system to enhance blood-brain barrier penetration and improve drug accumulation via integrin-mediated transcytosis/endocytosis and based on integrin overexpression in blood-brain barrier and glioma cells. The physicochemical characterization of RGD-PF-DP revealed a satisfactory size of 28.5±0.12 nm with uniform distribution and core-shell structure. The transport rates across the in vitro blood-brain barrier model, cellular uptake, cytotoxicity, and apoptosis of U87 malignant glioblastoma cells of RGD-PF-DP were significantly greater than those of non-c(RGDyK)-decorated Pluronic micelles. In vivo fluorescence imaging demonstrated the specificity and efficacy of intracranial tumor accumulation of RGD-PF-DP. RGD-PF-DP displayed an extended median survival time of 39 days, with no serious body weight loss during the regimen. No acute toxicity to major organs was observed in mice receiving treatment doses via intravenous administration. In conclusion, RGD-PF-DP could be a promising vehicle for enhanced doxorubicin and paclitaxel delivery in patients with brain glioma.

Dual-functional drug delivery system was developed by decorating c(RGDyK) (cyclic RGD [arginine-glycine-aspartic acid] peptide) with Pluronic polymeric micelles (c[RGDyK]-FP-DP) to overcome the drawbacks of low transport of chemotherapeutics across the blood-tumor barrier and poor multidrug-resistant (MDR) tumor therapy. c(RGDyK) that can bind to the integrin protein richly expressed at the site of tumor vascular endothelial cells and tumor cells with high affinity and specificity was conjugated to the N-hydroxysuccinimide-activated PEO terminus of the Pluronic F127 block copolymer. In this study, decreased tumor angiogenic and increased apoptotic activity in MDR cancer cells were observed after the treatment with c(RGDyK)-FP-DP. c(RGDyK)-FP-DP was fully characterized in terms of morphology, particle size, zeta potential, and drug release. Importantly, in vitro antiangiogenesis results demonstrated that c(RGDyK)-FP-DP had a significant inhibition effect on the tubular formation of human umbilical vein endothelial cells and promoted cellular apoptotic activity in MDR KBv cells. In addition, the growth inhibition efficacy of KBv tumor spheroids after crossing the blood-tumor barrier was obviously increased by c(RGDyK)-FP-DP compared to other control groups. Results suggested that c(RGDyK)-decorated Pluronic polymeric micelles can take pharmacological action on both human umbilical vein endothelial cells and KBv MDR cancer cells, resulting in a dual-functional anticancer effect similar to that observed in our in vitro cellular studies.

The therapeutic effect of methotrexate (MTX)-conjugated Pluronic-based polymeric mixed micelles (F127/P105-MTX) on the folate receptor-overexpressing tumors treatment was investigated in this study. Due to its high structural similarity to folic acid and the high expression of folate receptor in most solid tumors, MTX serves as not only a cytotoxic agent but also a homing ligand. Cellular uptake and the endocytic mechanism studies of MTX-conjugated mixed micelles were performed in folate receptor-rich KBv and folate receptor-deficient A-549 cancer cells. Additionally, the efficacy and safety studies of F127/P105-MTX in KBv tumor-bearing mice were evaluated. Results indicate that F127/P105-MTX significantly enhanced the cellular uptake in KBv cells as compared to that of conventional non-MTX-conjugated mixed micelles. Moreover, the results showed that F127/P105-MTX can be internalized by both caveolae- and clathrin-mediated endocytosis in energy-dependent and folate receptor-dependent manners. The in vitro and in vivo antitumor efficacies of F127/P105-MTX were significantly enhanced in comparison with MTX-entrapped mixed micelles. Furthermore, no acute toxicities to hematological system and major organs have been observed after intravenous administration during the regimen. Therefore, our results suggest that F127/P105-MTX could be an effective and safe nano-drug delivery system for cancer therapy, especially for the folate receptor-rich cancer treatment.

The aim of this work was to establish a novel polymeric mixed micelle composed of Pluronic P105 and F127 copolymers loaded with the poorly soluble antitumor drug docetaxel (DTX) against Taxol-resistant non-small cell lung cancer. A central composite design was utilized to optimize the preparation process, helping to improve drug solubilization efficiency and micelle stability. Prepared by a thin-film hydration method, the average size of the optimized mixed micelle was 23 nm, with a 92.40% encapsulation ratio and a 1.81% drug-loading efficiency. The optimized formulation showed high storage stability in lyophilized form, with 95.7% of the drug content remaining after 6 months' storage at 4°C. The in vitro cytotoxicity assay showed that the IC50 values for Taxotere(®) and mixed micelles were similar for A549, while on A549/Taxol cell lines, DTX-loaded P105/F127 mixed micelles showed a superior hypersensitizing effect; their IC50 value (0.059 μg/mL) was greatly reduced compared to those of Taxotere injections (0.593 μg/mL). The in vivo pharmacokinetic study showed that the mixed-micelle formulation achieved a 1.85-fold longer mean residence time in circulation and a 3.82-fold larger area under the plasma concentration-time curve than Taxotere. In addition, therapeutic improvement of mixed micelles in vivo against A549/Taxol was obtained. The tumor inhibition rate of the micelles was 69.05%, versus 34.43% for Taxotere (P < 0.01). Therefore, it could be concluded from the results that DTX-loaded P105/F127 mixed micelles might serve as a potential antitumor drug delivery system to overcome multidrug resistance in lung cancer.

The purpose of the present study was to optimize a solid lipid nanoparticle (SLN) of chloramphenicol by investigating the relationship between design factors and experimental data using response surface methodology. A Box-Behnken design was constructed using solid lipid (X(1)), surfactant (X(2)), and drug/lipid ratio (X(3)) level as independent factors. SLN was successfully prepared by a modified method of melt-emulsion ultrasonication and low temperature-solidification technique using glyceryl monostearate as the solid lipid, and poloxamer 188 as the surfactant. The dependent variables were entrapment efficiency (EE), drug loading (DL), and turbidity. Properties of SLN such as the morphology, particle size, zeta potential, EE, DL, and drug release behavior were investigated, respectively. As a result, the nanoparticle designed showed nearly spherical particles with a mean particle size of 248 nm. The polydispersity index of particle size was 0.277 ± 0.058 and zeta potential was -8.74 mV. The EE (%) and DL (%) could reach up to 83.29% ± 1.23% and 10.11% ± 2.02%, respectively. In vitro release studies showed a burst release at the initial stage followed by a prolonged release of chloramphenicol from SLN up to 48 hours. The release kinetics of the optimized formulation best fitted the Peppas-Korsmeyer model. These results indicated that the chloramphenicol-loaded SLN could potentially be exploited as a delivery system with improved drug entrapment efficiency and controlled drug release.

We proposed to develop a polycation lipid nanocarrier (PLN) with higher transfection efficiency than our previously described polycation nanostrucutred lipid nanocarrier (PNLC). PLN was composed of triolein, cetylated low-molecular-weight polyethylenimine, and dioleoyl phosphatidylethanolamine. The physicochemical properties of PLN and the PLN/DNA complexes (PDC) were characterized. The in vitro transfection was performed in human lung adenocarcinoma (SPC-A1) cells, and the intracellular mechanism was investigated as well. The measurements indicated that PLN and PDC are homogenous nanometer-sized particles with a positive charge. The transfection efficiency of PDC significantly increased with the content of triolein and was higher than that of PNLC and commercial Lipofectamine 2000. In particular, the transfection of PLN in the presence of 10% serum was more effective than that in its absence. With the help of specific inhibitors of chlorpromazine and filipin, the clathrin-dependent endocytosis pathway was determined to be the main contributor to the successful transfection mediated by PLN in SPC-A1 cells. The captured images verified that the fluorescent PDC was localized in the lysosomes and nuclei after endocytosis. Thus, PLN represents a novel efficient nonviral gene delivery vector.