Collagen/chitosan/genipin hydrogel loaded with phycocyanin nanoparticles and ND-336 for diabetic wound healing.

Diabetic wound healing remains a healthcare challenge due to the overexpression of matrix metalloproteinase-9 (MMP-9) and the imbalance between angiogenic factors and vascular inhibitory factors. In this study, we developed a nanocomposite injectable collagen/chitosan hydrogel for the treatment of delayed diabetic wound healing, which can promote cell migration to the wound site (through the addition of phycocyanin) and reduce the expression of MMP-9 (through the use of ND-336) to improve the therapeutic effect of diabetic wound healing. Furthermore, different weight ratios of collagen and chitosan hydrogels were prepared to select the hydrogel with proper mechanical properties. In vitro experiments confirmed that all hydrogels have favorable biocompatibility and hemocompatibility. Notably, Gel 2, with a weight ratio of collagen and chitosan at 25:75, was found to have an excellent capability to facilitate cell migration and in vivo studies further proved that Gel 2 nanocomposite hydrogel had the best ability to improve diabetic wound healing by promoting cell migration and decreasing MMP-9 expression. The collagen/chitosan/genipin hydrogel loaded phycocyanin and ND-336 can be harnessed for non-toxic and efficient treatment of wound healing management of diabetes.

Hollow Mesoporous Silica Nanoparticles for Dual Chemo-starvation Therapy of Hepatocellular Carcinoma.

PURPOSE: This study aims at chemotherapy and starvation therapy of HCC via starvation and apoptosis. METHODS: Hollow mesoporous organosilica nanoparticles (HMONs) with the thioether-hybrid structure were developed using an organic/inorganic co-templating assembly approach. Hydrofluoric acid was used to remove the internal MSN core for yielding large radial mesopores for loading drug cargos. The morphology and structure of NPs were determined using TEM and SEM. HMONs were stepwise surface modified with glucose oxidase (GOx), oxygen (O2) and Doxorubicin (DOX), and cancer cell membrane (CCM) for yielding CCM-coated HMONs (targeted stealth biorobots; TSBRs) for starvation, apoptotic, and enhanced cell uptake properties, respectively. The surface area and pore size distribution were determined via BET and BJH assays. The catalytic ability of GOx-modified NPs was measured using in vitro glucose conversion approach authenticated by H2O2 and pH determination assays. MTT assay was used to determine the cytotoxicities of NPs. Cell uptake and apoptotic assay were used for the NPs internalization and apoptosis mechanisms. The subcutaneous HepG2 tumor model was established in mice. The long-term in vivo toxicity was determined using blood assays. RESULTS: The prepared NPs were spherical, hollow and mesoporous with excellent surface area and pore size distribution. The GOx-modified NPs exhibited excellent catalytic activity. The TSBRs showed better cytotoxicity and reduce the tumor size and weight. The NPs showed long-term safety in vivo. CONCLUSION: TSBRs destroyed cancer cells by starvation and chemotherapy in both in-vitro and in-vivo settings which demonstrates its anti-cancer potential.

Cell-Membrane-Coated Cationic Nanoparticles Disguised as Macrophages for the Prevention and Treatment of Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by low-grade inflammation and insulin resistance. In this process, innate immune cells play a crucial role in recognizing the stimuli (free fatty acid, lipopolysaccharide, and cytokines) and mediating the inflammatory response, contributing to the development of T2DM. Neutralizing inflammatory cytokines and blocking the inflammation cascade provide great potential for the treatment of T2DM. Here, we applied a macrophage membrane as a bait, which could specifically recognize and bind the stimuli, to encapsulate nanoparticles and capture the stimuli, further preventing inflammation. The in vivo experiment results suggest that the nanoparticles could reduce the production of proinflammatory cytokines, decrease insulin resistance, and realize significant therapeutic effects for T2DM. A potential strategy is thus offered for blocking immune response, holding a wide application in metabolic and autoimmune diseases.

One-Step Fabrication of Multifunctional PLGA-HMME-DTX@MnO2 Nanoparticles for Enhanced Chemo-Sonodynamic Antitumor Treatment.

Background: Sonodynamic therapy (SDT) and its synergistic cancer therapy derivatives, such as combined chemotherapy-SDT (chemo-SDT), are promising approaches for tumor treatment. However, the main drawbacks restricting their applications are hypoxia in tumors and the reducing microenvironment or high glutathione (GSH) levels. Methods: In this study, a hybrid metal MnO2 was deposited onto nanoparticles fabricated using poly(lactic-co-glycolic acid) (PLGA), carrying docetaxel (DTX) and the sonosensitizer hematoporphyrin monomethyl ether (HMME) (PHD@MnO2) via a one-step flash nanoprecipitation (FNP) method. Characterization and in vitro and in vivo experiments were conducted to explore the chemo-SDT effect of PHD@MnO2 and evaluate the synergetic antitumor treatment of this nanosystem. Results: When low-power ultrasound is applied, the acquired PHD@MnO2, whether in solution or in MCF-7 cells, generated ROS more efficiently than other groups without MnO2 or those treated via monotherapy. Specifically, GSH-depletion was observed when MnO2 was introduced into the system. PHD@MnO2 presented good biocompatibility and biosafety in vitro and in vivo. These results indicated that the PHD@MnO2 nanoparticles overcame hypoxia in tumor tissue and suppressed the expression of hypoxia-inducible factor 1 alpha (HIF-1α), achieving enhanced chemo-SDT. Conclusion: This study provides a paradigm that rationally engineered multifunctional metal-hybrid nanoparticles can serve as an effective platform for augmenting the antitumor therapeutic efficiency of chemo-SDT.

A new approach based on CXCR4-targeted combination liposomes for the treatment of liver fibrosis.

Liver fibrosis results from excessive extracellular matrix accumulation due to injury and leads to cirrhosis, cancer, and death. Herein, we propose a chemokine receptor 4 (CXCR4)-targeted combination (CTC) liposomal therapy to treat carbon tetrachloride (CCl4)-induced liver fibrosis in a mouse model. This study aims to combine small molecules such as pirfenidone and AMD3100 in a single nanoplatform to investigate their synergistic antifibrotic effects in a setting of CCl4-induced liver fibrosis. CTC liposomes (CTC lipo) were prepared using the thin-film hydration method. CTC lipo exhibited a spherical shape, and the particle size was recorded at the nanoscale which confirms its appropriateness for in vitro and in vivo applications. CTC lipo had good storage and serum stability. The entrapped drugs in CTC lipo showed reduced toxicity at higher concentrations. CTC lipo displayed CXCR4 mediated cell uptake and were internalized by caveolae-mediated endocytosis. CTC lipo showed CXCR4 targeting and stromal cell-derived factor 1α (SDF1-α)/CXCR4 axis blocking activity. CTC lipo reduced the elevated serum aspartate aminotransferase (AST), alanine transaminase (ALT), and hydroxyproline (HYP) levels. The histological studies showed improved liver architecture and reduced collagen deposition after treatment. Transforming growth factor ß (TGFß), alpha-smooth muscle actin (α-SMA), and collagen I were elevated by CCl4 in comparison with the Sham. Upon CTC liposomal treatment, the quantitative score for the elevated fibrotic proteins such as TGFß, α-SMA, and collagen I was normalized. CTC lipo displayed significant downregulation of the upregulated TGFß, α-SMA, collagen I, and P-p38 expressions at the molecular level. The CXCR4 targeted liposomes showed prolonged biodistribution at 24 h. Our findings indicated that CTC lipo might be an alternative antifibrotic therapy that may offer new access to research and development. In a nutshell, the present study suggests that systemic administration of CTC lipo has efficient antifibrotic potential and deserves to be investigated for further clinical applications.

Ultrasmall iron oxide nanoparticles cause significant toxicity by specifically inducing acute oxidative stress to multiple organs.

BACKGROUND: Iron oxide nanoparticles have been approved by food and drug administration for clinical application as magnetic resonance imaging (MRI) and are considered to be a biocompatible material. Large iron oxide nanoparticles are usually used as transversal (T2) contrast agents to exhibit dark contrast in MRI. In contrast, ultrasmall iron oxide nanoparticles (USPIONs) (several nanometers) showed remarkable advantage in longitudinal (T1)-weighted MRI due to the brighten effect. The study of the toxicity mainly focuses on particles with size of tens to hundreds of nanometers, while little is known about the toxicity of USPIONs. RESULTS: We fabricated Fe3O4 nanoparticles with diameters of 2.3, 4.2, and 9.3 nm and evaluated their toxicity in mice by intravenous injection. The results indicate that ultrasmall iron oxide nanoparticles with small size (2.3 and 4.2 nm) were highly toxic and were lethal at a dosage of 100 mg/kg. In contrast, no obvious toxicity was observed for iron oxide nanoparticles with size of 9.3 nm. The toxicity of small nanoparticles (2.3 and 4.2 nm) could be reduced when the total dose was split into 4 doses with each interval for 5 min. To study the toxicology, we synthesized different-sized SiO2 and gold nanoparticles. No significant toxicity was observed for ultrasmall SiO2 and gold nanoparticles in the mice. Hence, the toxicity of the ultrasmall Fe3O4 nanoparticles should be attributed to both the iron element and size. In the in vitro experiments, all the ultrasmall nanoparticles (< 5 nm) of Fe3O4, SiO2, and gold induced the generation of the reactive oxygen species (ROS) efficiently, while no obvious ROS was observed in larger nanoparticles groups. However, the ·OH was only detected in Fe3O4 group instead of SiO2 and gold groups. After intravenous injection, significantly elevated ·OH level was observed in heart, serum, and multiple organs. Among these organs, heart showed highest ·OH level due to the high distribution of ultrasmall Fe3O4 nanoparticles, leading to the acute cardiac failure and death. CONCLUSION: Ultrasmall Fe3O4 nanoparticles (2.3 and 4.2 nm) showed high toxicity in vivo due to the distinctive capability in inducing the generation of ·OH in multiple organs, especially in heart. The toxicity was related to both the iron element and size. These findings provide novel insight into the toxicology of ultrasmall Fe3O4 nanoparticles, and also highlight the need of comprehensive evaluation for their clinic application.

Appropriate Size of Fe3O4 Nanoparticles for Cancer Therapy by Ferroptosis.

Iron oxide nanoparticles can induce cell death due to the ferroptosis mechanism, showing a great potential for cancer therapy. Here, we synthesized different-sized iron oxide nanoparticles (2-100 nm) to investigate their antitumor effect and toxicity mechanism. It was found that ultrasmall nanoparticles (< ∼5 nm) could accumulate in nucleus and were more efficient in triggering the generation of •OH than larger nanoparticles due to the quicker release of Fe2+, thus exhibiting more remarkable cytotoxicity. Nevertheless, 10 nm iron oxide nanoparticles group displayed the best antitumor effect in vivo. We studied the in vivo and intratumoral biodistribution of the nanoparticles and found that the therapeutic effects were related to both the tumoral accumulation and intratumoral distribution of nanoparticles. This work indicates the appropriate size of Fe3O4 NPs for cancer treatment and illustrates the possible factors that influence the therapeutic effect, suggesting the great potential of iron oxide in clinical application.

Design, synthesis and mechanistic studies of a TICT based fluorogenic probe for lighting up protein HSA.

Human serum albumin (HSA) in blood serves as an important biomarker for clinical diagnosis, and fluorescence sensing method has attracted extensive attention. In this work, a small organic molecule probe, YS8, involving twisted intramolecular charge transfer (TICT) characteristic, was designed and investigated to detect HSA. YS8 kept silent state in fluorescence under physiological conditions, but the encapsulation of YS8 in the hydrophobic subdomain IB region of HSA inhibited the TICT state and produced a clear light-up fluorescent signal. Especially, YS8 was demonstrated to be an efficient fluorogenic probe to discriminate HSA from other proteins including the bovine serum albumin (BSA). Moreover, YS8/HSA complex could be applied in fluorescence imaging in living cells and is also useful in the study of artificial fluorescent protein (AFP).

Ultrasound responsive self-assembled micelles loaded with hypocrellin for cancer sonodynamic therapy.

Nanoparticles have been demonstrated to be effective in targeted drug delivery to tumor due to the enhanced permeability and retention (EPR) effect. However, the inhomogeneous distribution of the nanoparticles in the tumor and the slow release of the drug make the therapeutic effect unsatisfied. Here, we present reactive oxygen species (ROS)-responsive micelles comprising poly (ethylene glycol)-poly(propylene sulfide) (PEG-PPS) for targeted delivery and in situ release of drug. Upon the irradiation of ultrasound, the loaded sonosensitizer hypocrellin (HC) will generate ROS to trigger the disassembly of the micelles and meanwhile realize sonodynamic therapy (SDT) effect of cancer. The in vivo experiment indicates that the HC loaded PEG-PPS are biocompatible and much more efficacious than an equivalent amount of free HC in inhibiting the growth of cancer.

CaO2/Fe3O4 nanocomposites for oxygen-independent generation of radicals and cancer therapy.

The hypoxic tumor environment prevents the generation of reactive oxygen species (ROS), reducing the therapeutic efficiency. We construct oleylamine (OA) coated CaO2/Fe3O4 nanocomposites to realize oxygen-independent generation of ROS and high efficient treatment of cancer. In the tumor site, CaO2 reacts with water to generate H2O2, which can be catalized by Fe2+ that is produced by Fe3O4, to form highly toxic hydroxyl radicals (∙OH). To inhibit the premature reaction, CaO2/Fe3O4 nanoparticles were coated with pH sensitive OA. The nanocomposites exhibited remarkable tumor growth inhibition ability and favorable biocompatibility, holding a great potential for hypoxic tumor therapy.

Phycocyanin Nanoparticle as a Novel Sonosensitizer for Tumor Sonodynamic Therapy of Michigan Cancer Foundation-7 Cells In Vitro.

The development of novel sonosensitizers with safety and efficiency is a key problem in anti-tumor sonodynamic therapy. Phycocyanin (PC) has been proved to have the singlet oxygen radicals (ROS) generation ability, and the potential of PC as a novel sonosensitizer has been investigated. To overcome the disadvantages of PC in vivo, such as poor stability and low half-life, PC nanoparticles (PCNP) were prepared by the cross-linking method. According to the results, PCNP has been found with good morphology, good particle size distribution and good stability. Human breast cancer cell line MCF-7 was used to investigate PCNP cell uptake ability. ROS generation and cytotoxicity under ultrasonic irradiation (sonotoxicity) were also studied on this cell. Under the condition of 0.75 w/cm² ultrasound, PCNP has a good ROS productivity and is equivalent to the sonotoxicity of the known sonosensitizer hematoporphyrin monomethyl Ether (HMME). In conclusion, PCNP is expected to be developed as an effective sonosensitizer for the sonodynamic therapy of tumors.

Concise Nanoplatform of Phycocyanin Nanoparticle Loaded with Docetaxel for Synergetic Chemo-sonodynamic Antitumor Therapy.

Combined chemotherapy and sonodynamic therapy (chemo-SDT) based on the nanoplatform/nanocarrier is a potential antitumor strategy that has shown higher therapeutic efficacy than any monotherapy. Therefore, a safe and effective multifunctional system with a concise design and simple preparation process is urgently needed. In this work, by using a one-step cross-linking method, a multifunctional nanosystem, which employs phycocyanin nanoparticles (PCNPs) as a nanocarrier to deliver the chemotherapy drug docetaxel (DTX) and a nanosonosensitizer to generate reactive oxygen species (ROS), was prepared and evaluated (PCNP-DTX). Under low-intensity ultrasound irradiation, PCNP-DTX retained the ROS generation ability of phycocyanin and caused the destruction of mitochondrial potential. PCNP was also revealed to be an acidic and ultrasound-sensitive carrier with good biocompatibility. In addition to its cumulation behavior in tumors, PCNP can achieve tumor-targeted delivery and release of DTX. PCNP-DTX has also been proven to have a significant chemo-SDT synergy effect when low-intensity ultrasound was applied, showing enhanced antitumor activity both in vitro and in vivo. This study provides a concise yet promising nanoplatform based on the natural protein phycocyanin for achieving an effective, targeted, and synergetic chemo-SDT for antitumor therapy.

Cancer stem cells and strategies for targeted drug delivery.

Cancer stem cells (CSCs) are a small proportion of cancer cells with high tumorigenic activity, self-renewal ability, and multilineage differentiation potential. Standard anti-tumor therapies including conventional chemotherapy, radiation therapy, and molecularly targeted therapies are not effective against CSCs, and often lead to enrichment of CSCs that can result in tumor relapse. Therefore, it is hypothesized that targeting CSCs is key to increasing the efficacy of cancer therapies. In this review, CSC properties including CSC markers, their role in tumor growth, invasiveness, metastasis, and drug resistance, as well as CSC microenvironment are discussed. Further, CSC-targeted strategies including the use of targeted drug delivery systems are examined.

Optimization of activity localization of quinoline derivatives: Design, synthesis, and dual evaluation of biological activity for potential antitumor and antibacterial agents.

A novel of quarternary amine around a quinolinium iodide combined with even number alkyl chain were prepared in a several step in moderate yield starting from malonic ester and benzo[d][1,3]dioxol-5-amine. All of the active structure compounds were identified by nuclear magnetic resonance (NMR), such as 1H NMR, 13C NMR, infrared radiation (IR), high resolution mass spectrometry (HR-MS) and Carlo Erba Instruments CHNS-O EA1108 spectra analysis. With regard to the anticancer properties, the in vitro cytotoxicity against three human cancer cell lines (A-549, Hela and SGC-7901) were evaluated. The antibacterial properties against two human bacterial strains, Escherichia coli (ATCC 29213) and Staphylococcus aureus (ATCC 8739), along with minimum inhibitory concentration (MIC) values were evaluated. The target compounds, 5-12, exhibited significant antitumor and antibacterial activity, of which compound 12 was found to be the most potent derivative with IC50 values of 5.18 ± 0.64, 7.62 ± 1.05, 17.59 ± 0.41, and 54.45 ± 4.88 against A-549, Hela, SGC-7901, and L-02 cells, respectively, stronger than the positive control 5-FU and MTX. Furthermore, compound 12 had the most potent inhibitory activity. The MIC of this compound against Escherichia coli (ATCC 29213) and Staphylococcus aureus (ATCC 8739) was 3.125 nmol·mL-1, which was smaller than that of the reference agents, amoxicillin and ciprofloxacin.

Design, Synthesis, and Dual Evaluation of Quinoline and Quinolinium Iodide Salt Derivatives as Potential Anticancer and Antibacterial Agents.

A series of novel quinoline and quinolinium iodide derivatives were designed and synthesized to discover potential anticancer and antibacterial agents. With regard to anticancer properties, in vitro cytotoxicities against three human cancer cell lines (A-549, HeLa and SGC-7901) were evaluated. The antibacterial properties against two strains, Escherichia coli (ATCC 29213) and Staphylococcus aureus (ATCC 8739), along with minimum inhibitory concentration (MIC) values were evaluated. The target alkyliodine substituted compounds exhibited significant antitumor and antibacterial activity, of which compound 8-((4-(benzyloxy)phenyl)amino)-7-(ethoxycarbonyl)-5-propyl-[1,3]dioxolo[4,5-g]quinolin-5-ium (12) was found to be the most potent derivative with IC50 values of 4.45±0.88, 4.74±0.42, 14.54±1.96, and 32.12±3.66 against A-549, HeLa, SGC-7901, and L-02 cells, respectively, stronger than the positive controls 5-FU and MTX. Furthermore, compound 12 had the most potent bacterial inhibitory activity. The MIC of this compound against both E. coli and S. aureus was 3.125 nmol ⋅ mL-1 , which was smaller than that against the reference agents amoxicillin and ciprofloxacin.

Magnetic thermosensitive micelles with upper critical solution temperature for NIR triggered drug release.

Smart micelles which undergo dramatic property changes in response to temperature have aroused extensive interest in specific cancer therapy. To date, studies on thermosensitive polymers have mainly focused on lower critical solution temperature (LCST) polymers. Materials with upper critical solution temperature (UCST) which can swell and disassemble at elevated temperatures have much less been documented, although they have been reported to be ideal carriers for quick and complete drug release upon applying a stimulus. Here, magnetic micelles with UCST are developed for doxorubicin (DOX) delivery. Hydrophobic Fe3O4 magnetic nanoparticles with a particle size of 8 nm are fabricated and enveloped in an amphiphilic polymer, poly(AAm-co-AN)-g-PEG (PAAP), to form UCST micelles (Fe3O4@PAAP). The resulting micelles exhibit excellent photothermal effects and burst drug release in response to near infrared (NIR) laser irradiation. The in vitro and in vivo antitumor experiments indicate that DOX-Fe3O4@PAAP micelles can significantly enhance the therapeutic effect upon NIR light irradiation. A novel thermosensitive platform is thus offered for in situ drug release and combined photothermal-chemotherapy, holding a favorable prospect for cancer therapy.

Alginate/chitosan microcapsules for in-situ delivery of the protein, interleukin-1 receptor antagonist (IL-1Ra), for the treatment of dextran sulfate sodium (DSS)-induced colitis in a mouse model.

Targeted delivery of bioactive compounds such as proteins to the colon has numerous advantages for the therapeutic treatment of inflammatory bowel disease. The present study sought to fabricate alginate/chitosan microcapsules containing IL-1Ra (Alg/Chi/IL-1Ra MC) via a single-step electrospraying method. Two important factors of efficacy were measured-the pH-responsiveness of the microcapsule and the in-vitro drug release profile. The DSS-induced colitis mouse model was used to evaluate the therapeutic effect of the Alg/Chi/IL-1Ra microcapsules, with results showing the protective effect of the Alg/Chi microcapsules for the passage of IL-1Ra through the harsh environment of the upper gastrointestinal tract. This effect was owing to the pH-sensitive response of the microcapsule, which allowed the targeted release of IL-1Ra in the colon. DAI evaluation, colon length, colon tissue morphology, histologic damage scores and relative protein concentrations (MPO, TNF-α and IL-1ß) demonstrated that the Alg/Chi/IL-1Ra microcapsules alleviated DSS-induced colitis in mice. The present study thus demonstrates a practical means of oral delivery of proteins, in-situ colon release, and a promising application of IL-1Ra in the treatment of autoimmune and inflammatory diseases.

Engineered nanoparticles disguised as macrophages for trapping lipopolysaccharide and preventing endotoxemia.

Endotoxemia is a severe pathophysiology induced by bacterial endotoxin (also known as lipopolysaccharide, LPS), causing high mortality in clinic due to the life-threatening syndromes, such as sepsis, shock, and multiple organ dysfunction. Removing or neutralizing endotoxin from the circulatory system has been proven to be a potential strategy for the treatment of endotoxemia. However, the selectivity and removal efficiency of existing detoxification approaches are not satisfied. Considering the crucial role of immune cells in LPS recognition and inflammation mediation, we design a disguised nanoparticle using macrophage membranes as bait to specifically capture and deactivate LPS. The in vivo experiment results demonstrate that the nanoparticles markedly weaken the immune response, reduce the inflammatory reaction, and improve the survival rate of endotoxic mice. These deceptive nanoparticles should be broadly applicable for treating a variety of diseases related to LPS, such as metabolic and vascular abnormalities in obesity, and diabetes-related diseases.

Magnetic liposomes for light-sensitive drug delivery and combined photothermal-chemotherapy of tumors.

The targeted delivery of anticancer drugs for improving the therapeutic efficacy and reducing the side effects has attracted great attention in cancer therapy. In this study, multifunctional magnetic nanoparticles-loaded thermosensitive liposomes (Fe3O4-TSL) were developed for the near-infrared (NIR) laser-triggered release and combined photothermal-chemotherapy of tumors. Doxorubicin (DOX) was encapsulated into the Fe3O4-TSL (DOX-Fe3O4-TSL) via an ammonium sulfate gradient, with an encapsulation efficiency of up to 90.9%. Once treated with NIR laser irradiation, significantly improved drug release was observed in the DOX-Fe3O4-TSL compared to that of DOX-TSL. After an intravenous injection, Fe3O4-TSL tended to enrich in the tumor over time and showed remarkable magnetic resonance imaging (MRI) and photothermal effects. The combined chemo-photothermal therapy study demonstrated that DOX-Fe3O4-TSL could significantly inhibit the tumor growth without causing any significant damage to normal tissues under NIR laser irradiation. These results revealed a great potential for DOX-Fe3O4-TSL for the diagnosis and synergistic therapy of tumors.

Effect of magnetic nanoparticles size on rheumatoid arthritis targeting and photothermal therapy.

Nanoparticles based multifunctional system exhibits great potential in diagnosis and therapy of rheumatoid arthritis (RA). The size of nanoparticles plays an essential role in biodistribution and cellular uptake, in turn affects the drug delivery efficiency and therapeutic effect. To investigate the optimal size for RA targeting, Fe3O4 nanoparticles with well-defined particle sizes (70-350 nm) and identical surface properties were developed as model nanoparticles. The synthesized Fe3O4 nanoparticles exhibited excellent biocompatibility and showed higher temperature response under irradiation of near infrared light. Size-dependent internalization was observed when incubated with inflammatory cells. Compared with large ones, small nanoparticles were more readily be phagocytized, leading to higher cytotoxicity in vitro. However, the in vivo experiment in CIA mice demonstrated a quite different result that nanoparticles with size of 220 nm exerted better accessibility to inflamed joint and resulted in higher temperature and better therapeutic effect under laser irradiation. This study not only offered a novel method for RA therapy but also a guideline for RA targeted drug carrier design.