Synergistic Dose Permutation of Isolated Alkaloid and Sterol for Anticancer Effect on Young Swiss Albino Mice

Introduction

Synergy is defined as an interaction of some substances that cooperate to give rise to the combined effect greater than the sum of their individual effects. It is a natural strategy that has evolved by nature to more efficacy with low cost.

Methods

This study is designed to evaluate the chemopreventive effect of a combined drug sample which is prepared by mixing an equal portion of stigmasterol and palmatine isolated from Azadirachta indica and Tinospora cordifolia respectively at a concentration of 100 mg/kg and 200 mg/kg body weight during the whole concentration.

Results

At the end of the study, it was found that this combined drug sample decreased the number of tumors and their size. This drug significantly reduced the serum level of glutamate pyruvate transaminase, alkaline phosphatase, glutamate oxalate transaminase, and bilirubin and enhanced the level of oxidative enzyme level of glutathione, superoxide dismutase, and catalase, and inhibit the level of lipid peroxides.

Discussion

The result suggests that combined drug samples exhibit a chemopreventive effect which is better than the effect of individual drugs (stigmasterol and palmatine).

Injectable Reactive Oxygen Species-Responsive SN38 Prodrug Scaffold with Checkpoint Inhibitors for Combined Chemoimmunotherapy

Chemotherapeutic agents have been widely used for cancer treatment in clinics. Aside from their direct cytotoxicity to cancer cells, some of them could activate the immune system of the host, contributing to the enhanced antitumor activity. Here, the reactive oxygen species (ROS)-responsive hydrogel, covalently cross-linked by phenylboronic acid-modified 7-ethyl-10-hydroxycamptothecin (SN38-SA-BA) with poly(vinyl alcohol) (PVA), is fabricated for topical delivery of anti-programmed cell death protein ligand 1 antibodies (aPDL1). In the presence of endogenous ROS, SN38-SA-BA will be oxidized and hydrolyzed, leading to the degradation of hydrogel and the release of initial free SN38 and encapsulated aPDL1. It is demonstrated that SN38 could elicit specific immune responses by triggering immunogenic cell death (ICD) of cancer cells, a distinct cell death pathway featured with the release of immunostimulatory damage-associated molecular patterns (DAMPs). Meanwhile, the released aPDL1 could bind to programmed cell death protein ligand 1 (PDL1) expressed on cancer cells to augment antitumor T cell responses. Thus, the ROS-responsive prodrug hydrogel loaded with aPDL1 could induce effective innate and adaptive antitumor immune responses after local injection, significantly inhibiting or even eliminating those tumors.

Scaffold-mediated sequential drug/gene delivery to promote nerve regeneration and remyelination following traumatic nerve injuries

Neural tissue regeneration following traumatic injuries is often subpar. As a result, the field of neural tissue engineering has evolved to find therapeutic interventions and has seen promising outcomes. However, robust nerve and myelin regeneration remain elusive. One possible reason may be the fact that tissue regeneration often follows a complex sequence of events in a temporally-controlled manner. Although several other fields of tissue engineering have begun to recognise the importance of delivering two or more biomolecules sequentially for more complete tissue regeneration, such serial delivery of biomolecules in neural tissue engineering remains limited. This review aims to highlight the need for sequential delivery to enhance nerve regeneration and remyelination after traumatic injuries in the central nervous system, using spinal cord injuries as an example. In addition, possible methods to attain temporally-controlled drug/gene delivery are also discussed for effective neural tissue regeneration.

Spatiotemporally and Sequentially-Controlled Drug Release from Polymer Gatekeeper-Hollow Silica Nanoparticles

Combination chemotherapy has become the primary strategy against cancer multidrug resistance; however, accomplishing optimal pharmacokinetic delivery of multiple drugs is still challenging. Herein, we report a sequential combination drug delivery strategy exploiting a pH-triggerable and redox switch to release cargos from hollow silica nanoparticles in a spatiotemporal manner. This versatile system further enables a large loading efficiency for both hydrophobic and hydrophilic drugs inside the nanoparticles, followed by self-crosslinking with disulfide and diisopropylamine-functionalized polymers. In acidic tumour environments, the positive charge generated by the protonation of the diisopropylamine moiety facilitated the cellular uptake of the particles. Upon internalization, the acidic endosomal pH condition and intracellular glutathione regulated the sequential release of the drugs in a time-dependent manner, providing a promising therapeutic approach to overcoming drug resistance during cancer treatment.

Doxorubicin-loaded redox-responsive amphiphilic dendritic porphyrin conjugates for chemotherapy and photodynamic therapy

The reduction-responsive dendritic copolymer (TPP-S-S-G3) was developed to construct a drug carrier for encapsulation of hydrophobic drug (DOX) for the combination treatment between chemotherapy and PDT.

Self-coated interfacial layer at organic/inorganic phase for temporally controlling dual-drug delivery from electrospun fibers

Implantable tissue engineering scaffolds with temporally programmable multi-drug release are recognized as promising tools to improve therapeutic effects. A good example would be one that exhibits initial anti-inflammatory and long-term anti-tumor activities after tumor resection. In this study, a new strategy for self-coated interfacial layer on drug-loaded mesoporous silica nanoparticles (MSNs) based on mussel-mimetic catecholamine polymer (polydopamine, PDA) layer was developed between inorganic and organic matrix for controlling drug release. When the interface PDA coated MSNs were encapsulated in electrospun poly(L-lactide) (PLLA) fibers, the release rates of drugs located inside/outside the interfacial layer could be finely controlled, with short-term release of anti-inflammation ibuprofen (IBU) for 30 days in absence of interfacial interactions and sustained long-term release of doxorubicin (DOX) for 90 days in presence of interfacial interactions to inhibit potential tumor recurrence. The DOX@MSN-PDA/IBU/PLLA hybrid fibrous scaffolds were further found to inhibit proliferation of inflammatory macrophages and cancerous HeLa cells, while supporting the normal stromal fibroblast adhesion and proliferation at different release stages. These results have suggested that the interfacial obstruction layer at the organic/inorganic phase was able to control the release of drugs inside (slow)/outside (rapid) the interfacial layer in a programmable manner. We believe such interface polymer strategy will find applications in where temporally controlled multi-drug delivery is needed.