A Chemical Strategy of Developing Resistance-Proof, Immune-Friendly Drugs

巧妙的合成策略已被用于开发强效药物，如抗生素和化疗药物，但同时细菌和癌细胞也发展出了耐药性机制。事实证明，这种耐药性对病人来说是毁灭性的，对医生来说是令人困惑的。我们提出了一种新的想法，即使用简单而可逆的化学修饰来增强药物对耐药生物和细胞的抗性。作为原理证明，我们建议使用一些化疗药物（CAs）作为修饰药物。癌细胞对CAs产生了耐药性，而很少分裂的癌症干细胞对CAs具有难治性。这促使使用更高剂量的CAs，导致正常细胞（如免疫细胞）死亡，从而使患者暴露于经常压倒它们的感染。包括我们在内的许多研究小组进行的广泛研究表明，膳食多酚姜黄素（CC）消除化疗耐药，杀死癌症干细胞，并刺激肿瘤相关的先天免疫细胞（小胶质细胞），将它们从促肿瘤（M2）状态转化为杀肿瘤（M1）状态。然而，CC本身在含水体液中很少溶解，并且在体内降解迅速，这导致生物利用度差。利用CC的有益特性，我们将采用创新的单步化学方法，将CC与紫杉醇、吉西他滨、阿霉素和甲氨蝶呤这四种原型CAs连接起来，通过细胞内酯酶和氨基酶在加合物进入癌细胞时裂解化学键，释放CA和CC，以稳定和溶解加合物，并使其能够通过血脑屏障和其他膜。我们将采用既定的策略，将药物封装到具有生物相容性的壳聚糖-碳点杂化纳米凝胶中，该纳米凝胶具有在低ph肿瘤微环境中智能释放加合物的能力。然后将纳米凝胶形式的每种加合物（称为Stomalignum）在消除培养中的患者来源的GBM干细胞方面的功效与同源的纳米凝胶封装的CA单独（称为Apo-Stomalignum）进行比较。我们期望Stomalignum能够释放CC来有效地清除GBM干细胞，而这些细胞应该对同源Apo-Stomalignum具有抗性。随后，我们将利用我们建立的GBM原位小鼠模型，比较Stomalignum与相应的Apo-Stomalignum在体内的抗癌效果。我们期望每个Stomalignum都能以比相应的Apo-Stomalignum所需的剂量低得多的剂量拯救GBM小鼠。该项目的目标是开发一个耐药，免疫友好，新一代，安全的ca家族。该项目还将为三个实验室先后培养本科生科研人员提供良好的平台。他们将合成每种加合物，将其封装，然后将Stomalignum与同源的Apo-Stomalignum一起用于抗癌活性的生物测试。

Clever synthetic strategies have been used to develop highly potent drugs such as antibiotics and chemotherapeutic agents, but concurrently bacteria and cancer cells have also developed mechanisms of resistance. Such drug-resistance is proven to be devastating for patients and bewildering for the physicians. We submit the novel idea of potentiating drugs against resistant organisms and cells using simple yet reversible chemical modification. As a proof of principle, we propose to use some chemotherapeutic agents (CAs) as drugs for modification. Cancer cells develop resistance to CAs and the rarely-dividing cancer stem cells are refractory to CAs. This prompts the use of higher doses of the CAs, which results in the death of normal cells such as the immune cells, thereby exposing the patients to infections that often overpower them. Extensive studies performed by many groups including ours establish that the dietary polyphenol curcumin (CC) eliminates chemoresistance, kills cancer stem cells, and stimulates tumor-associated innate immune cells (microglia), converting them from a tumor-promoting (M2) to a tumoricidal (M1) state. However, CC per se is sparingly soluble in the aqueous body fluids and undergoes rapid degradation in vivo, which results in poor bioavailability. Capitalizing on the beneficial properties of CC, we will apply innovative, single-step chemistry to link CC to each of four prototypic CAs, Paclitaxel, Gemcitabine, Doxorubicin, and Methotrexate, through chemical bonds that would be cleaved by intracellular esterases and amidases upon entry of the adduct into cancer cells to release CA and CC. To stabilize and solubilize the adducts and enable their transit through the blood-brain barrier and other membranes, we will use our established strategy of encapsulating drugs into biocompatible chitosan-carbon dot hybrid nanogels with the capacity of smart release of adduct in the low-pH tumor micro-environment. The efficacy of the nanogel form of each adduct (named as Stomalignum) in eliminating patient-derived GBM stem cells in culture will then be compared with the cognate nanogel-encapsulated CA alone (named as Apo-Stomalignum). We expect that the Stomalignum would release CC to efficiently eliminate GBM stem cells whereas these cells should be resistant to the cognate Apo-Stomalignum. Subsequently, the anticancer efficacy of Stomalignum in vivo will be compared with that of the corresponding Apo-Stomalignum using our well-established orthotopic mouse model of GBM. We expect that each Stomalignum will be able to rescue the GBM mice at a much lower dose than required for the corresponding Apo-Stomalignum. The objective of this project is to develop a family of chemoresistance-proof, immune-friendly, new-generation, safe CAs. This project will also provide an excellent platform to train undergraduate researchers successively in three laboratories. They will synthesize each adduct, encapsulate it, and then use the Stomalignum alongside the cognate Apo-Stomalignum in biological tests for anti-cancer activity.