| BackgroundLiver cancer is the sixth common types of cancer and the third lethal cancer allover the world. It has the highest incidence rate in China, and it accounts for55%incidence and45%mortality in the world. Currently, there are about320,000cases ofpatients died of liver cancer every year in China. Several factors contribute to themain cause of liver cancer death, such as absence of targeting for chemotherapy drugsand toxicity of normal organs, and uncontrolled recurrence and metastasis of livercancer, etc. Therefore, improving the tumor chemotherapy drug targeting, reducing itstoxicity to normal tissues, and inhibiting tumor recurrence and metastasis are of greattheoretical and practical significance.In recent years, many traditional Chinese medicines were used to treat tumor.The effect and mechanism on antitumor monomeric compound from Chinesemedicine were extensively studied till now. Berberine is an isoquinoline alkaloid witha long history of use in traditional medicine. It can be isolated from several plants ofthe genera Berberis and Coptis, including goldenseal, Oregon grape, and barberry.Berberine has extensive pharmacological effects, such as antibacterial,anti-inflammatory, high blood pressure, diabetes, hyperlipidemia. Recent studies havereported that berberine has anticancer activities against several types of tumors,including colon cancer, stomach cancer, esophagus cancer and prostate cancer, etc.Our previous studies showed that berberine not only inhibited the growth of mice H22hepatocarcinoma, but also suppress the recurrence and metastasis of liver cancer invitro. Moreover, berberine showed lower toxicity on organs even administrating alarge dosage or a long term. Therefore, berberine has a potential to be a promisingantitumor drug in the future. However, the drawbacks of berberine, such as poor oralabsorption, low oral bioavailability and absence of targeting, are restricted its clinicalapplications. As a result, there’s an urgent need to develop a drug carrier to load berberine,and the carrier should possess the properties as following:(1) Passive targeting, activetargeting or physical-chemistry target to tumor cells: Passive targeting means thatparticle size smaller than200nm can easily pass through the tumor blood vessels withenhanced retention and permeability. Active targeting carriers were usually modifiedwith antibodies, ligand or tumor specific molecular (2) Biocompatibility: drug carriershould prepare with good biocompatibility, biodegradable and low toxicity ofmaterials, which would prolong the circulating time in the blood system and reduce oravoid the phagocytosis of mononuclear macrophage system.(3) Controlled releasingdrugs: Responsive mechanisms including pH response, thermal response, or magneticresponse were engineered to the drug carriers to achieve controlling release of drug intime or space. Therefore, drug carriers with aforementioned characteristics are the keyto solve shortcoming of berberine in cancer therapy.Recently, development of nanometer medicine provides a new way to elevatedrug targeting and nanometer delivery system has been widely applied in systemiccancer drug delivery. Magnetic nanoparticle drug delivery system, composed ofmagnetic nanoparticles and mesoporous silica, was successfully used in theranostic oftumor due to its unique properties. Our preliminary work has successfully developedJanus-magnetic mesoporous silica nanorod (Fe3O4-MSN), which avoid lowmagnetic property of spherical core-shell structure, and has excellent character inlarge preload, good biocompatibility, high cell endocytosis, pH responsiveness, MRIimaging and low toxicity. On the basis of stable synthesis technology, we has beenloaded chemotherapy drugs doxorubicin (DOX) and achieved high loading capacity,but very low loading capacity for berberine, Herein, we tied to improve berberineloading by altering Janus-magnetic mesoporous silica nanorod reaction system withdifferent methods, one is by using1,3,5-trimthylbenzene (TMB) enlargingmesoporous size to increase preload, the second is through modulating CTAB contentto elevate loading capacity, and the third is by elevating the solubility and dispesivityof berberine in DMSO to increase the berberine loading, then the morphology andloading drug properties were investigated one by one. Finally, the biosafety andantitumor effect of magnetic mesoporous silica nanocarrier loading berberine systemwere evaluated in HepG2cell lines.Contents (1)Synthesis of magnetic mesoporous silica by using1,3,5-trimthylbenzene (TMB)to enlarge mesoporous size, characterilization and evaluating preloadLarge aperture Janus type magnetic-mesoporous silica nanoparticle carrier(Fe3O4-MSN), was synthesized by broaching method with expanding agent TMB,and then berberine was loaded after modifying the surface of the mesoporous silicawith functional mesoporous silica–COOH group, a protocol was set up by adjustingthe reaction conditions and the amount of reactants, the standard is that the particlesize is less than200nm, efficient load of aperture is greater than5nm. Finally,Fe3O4-MSN nanoparticle was characterized and drug loading in vitro was evaluated.(2) Modulating the concentration of template agent CTAB to changenanoparticle morphology to increase preload.Shell-core structure nanoparticle was synthesized by increasing the concentrationof CTAB template agent in reaction system, and then berberine was loaded aftermodifying the surface of the mesoporous silica with functional mesoporous silica–COOH group. Finally, nanoparticle (Fe3O4-MSN) were characterized and drugloading in vitro was evaluated.(3) Increase the berberine loading by elevating the solubility and dispersivity ofberberine in DMSO-Janus Fe3O4-MSN reaction system.Firstly Janus magnetic-mesoporous silica nanoparticle carrier (Fe3O4-MSN)was synthesized and modified the surface of the mesoporous silica with–COOHgroup, and then berberine dissolved in dimethyl sulfoxide (DMSO) was added to thereaction system, morphology and physical-chemical properties of Janus Fe3O4-MSN were characterized，drug loading and drug releasing in vitro were evaluated.Finally, the biosafety and antitumor effect of Janus Fe3O4-MSN loading berberinesystem were evaluated in HepG2cell lines.Results1. The two methods that Synthesis of large-pore magnetic mesoporous silica byusing TMB and modulation of the concentration of template agent CTAB could notincrease the preload of berberine in nanoparticles, and the method that increasing theberberine loading by elevating the solubility and dispersivity of berberine in DMSO-Janus Fe3O4-MSN reaction system could significant increased the berberine preload,the loading efficiency rate is about47%and loading capacity is about20%. 2. Morphology characterization and identification were carried out bytransmission electron microscopy, scanning electron microscopy (SEM), vibrationmagnetometer, and ultraviolet spectrophotometry. It is shown amorphous statenanoparticles by TMB enlarging pore method; shell-core nanoparticles by modulationof the concentration of CTAB were synthesized. By using the method that increasingberberine loading by elevating the solubility and dispersivity of berberine in DMSO-Janus Fe3O4-MSN reaction system, we prepared the Janus Fe3O4-MSN/Ber withshape consistency and good dispersivity.3. Janus Fe3O4-MSN nanocarrier has good biosafety and no toxicity under50μg/ml. HepG2cell viability was inhibited by Janus Fe3O4-MSN/Ber nanocarrier systemin dose dependent manner, the concentration of Janus Fe3O4-MSN/Ber nanocarrierranging from12.5μg/ml to50μg/ml（equal to the concentration of berberine2.5μg/ml to10μg/ml）has relative higher cell killing effect, comparing to the respectiveberberine group.Conclusion1. The two methods that TMB enlarging pore and modulation of theconcentration of CTAB could not increase the preload of berberine in nanoparticles,and the method that increasing the berberine loading by elevating the solubility anddispersivity of berberine in DMSO-Janus Fe3O4-MSN reaction system couldsignificant increased the berberine preload, the loading efficiency rate is about47%and loading capacity is about20%.2. Janus Fe3O4-MSN nanocarrier has no toxicity under50μg/ml. HepG2cellviability was inhibited by Janus Fe3O4-MSN/Ber nanocarrier system in dosedependent manner, the concentration of Janus Fe3O4-MSN/Ber nanocarrier rangingfrom12.5μg/ml to50μg/m（lequal to the concentration of berberine2.5μg/ml to10μg/ml）has relative higher cell killing effect, comparing to the respective berberinegroup. |
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