Studies On The Intratumoral Injections And Percutaneous Administrations Of Cucurbitacin

Cancer has become a kind of serious disease to threaten the human's life and life qualities.The cancer therapeutics included the surgery,radio-or chemotherapy and biological therapy etc.Then with the disease development,the palliative care should to be important.However,due to the higher side effects of the chemical drugs with the systemic used,the localized therapy was attracted more attentions during studies.And in the last stage of the cancer,the palliative care aimed to improve the patients' life qualities was got more approbation with the clinicians and patients.In this study,cucurbitacin(Cuc),which was extracted from traditional Chinese medicine and displayed with multiple bioactivities,was selected as the model drug.The studies included(1)Cuc-loaded intratumoral injections,which was expected to enhance the local drug concentration thus reducing the systemic exposure,and(2)Cuc microemulsion,which was expected to improve the life qualities on the late stage cancer patients.The first part was focus on the Cuc-loaded intratumoral injection and its anti-melanoma efficiencies.In this part,multidispersed particle system and in situ-forming implants were investigated both on their in vitro and in vivo properties.The Cuc-loaded PLGA particles of different sizes(about 50?m,5?m,and 270nm,respectively)were prepared by the solvent emulsified-evaporated method,and their physicochemical properties,in vitro cytotoxicity,particles-cells interactions,pharmacokinetics and pharmacodynamics were systemically investigated for the first time.And then,two types of in situ-forming implants(ISFIs),PLGA-ISFI and SAIB-ISFI,were investigated for their in vitro release and anti-melanoma efficiencies with intratumoral injection.The second part was focus on the Cuc microemulsion preparations and applications.In this part,microemulsion was evaluated by its phase behavior and in vitro skin permeation.The tumor bearing mice's body weight changes,the tumor volume increased percentage,the daily water and food uptake amount,spontaneous activities and survival time were selected to evaluate the palliative caring efficiencies.Meanwhile,the biomarker-the serum free DNA was determined to reveal the palliative care efficiencies of various treatments.Finally,the permeation enhancing mechanism was studied for the microemulsion.The experiments of the intratumoral injection of Cuc-loaded PLGA particles showed that Cuc raw material and NPs(Cuc-loaded nanoparticles,about 270nm)showed higher initial burst release in vitro and higher drug concentration in tumor and in plasma.While large particles(about 50?m)showed lower initial burst and slow drug release,which would not supply enough amount of drug to inhibit the cancer cell growth during the whole treatment period.Particles with mean diameter of about 5?m performed the best anti-melanoma efficiencies both in vitro and in vivo.The release patterns,instead of the particles-cells interactions,would be the key factors to affect the biological effects of the particulate system for intratumoral injection.And then,during the studies on the anti-melanoma efficiencies of Cuc-loaded ISFIs,the results indicated that different release patterns appeared in the two ISFIs systems,due to the different natures of two carrier molecules.The solvent used in ISFIs also had an impact on the release patterns.The results revealed that SAIB ISFIs displayed better kinetic parameters and therapeutic efficiencies.Evaluations of administration methods also indicated that multi-point injection displayed better efficiency than single-point injection.The experiments of the preparation and applications of microemulsion showed that the optimized formulation was constituted with Azone(oil),Tween80(surfactant),ethanol(cosurfactant)and water at the ratio of 2.5:16.9:5.6:75(w/w/w/w).And then,the pharmacodynamic studies revealed that combined with classical chemical-therapy drug,Cuc microemulsion would display the potential effectiveness in cancer palliative cares.The results showed that the mainly mechanisms of the microemulsion to enhance the Cuc penetration were as the following,(1)the microemulsion could dramatically increase the drug solubility in aqueous medium,means increased the freedom degree of the drug;and(2)the components in microemulsion,such as Azone and ethanol,could disturb the lipid aggregations exists in stratum corneum,thus reduced the penetration resistances of the drug.After the all,we also confirmed that the microemulsion particles could not penetrate through the epidermal layer but to accumulate in the stratum corneum layer to form a drug "reservoir"in the skin surface.Moreover,the microemulsion could reach to the skin deep layer through some skin duct-like adnexal,such as hair follicles and sweat glands.However,these routes were limited to the benefits of drug penetrations.Based on the cytotoxicity experiments and pharmacokinetic\pharmacodynamic studies,we concluded that the release patterns of the particles would strongly affect the biological efficiency not only at the cell level but also in two types of animal models.And due to the high pressure in solid tumor,the particle would leak out through the pinhole thus inducing the side effects.During the experiments,SAIB-ISFI displayed excellent properties both in vitro and in vivo,and it could to be a potential carrier used in intratumor injection.The microemulsion could dramatically increase the skin penetration of Cuc,and Cuc microemulsion displayed potential applications in palliative care with the combination of chemical drug.