Current update of a thermosensitive liposomes composed of DPPC and Brij78

Thermo- and pH-responsive targeted lipid-coated mesoporous nano silica platform for dual delivery of paclitaxel and gemcitabine to overcome HER2-positive breast cancer

In the current study, a new monoclonal antibody conjugated dual stimuli lipid-coated mesoporous silica nanoparticles (L-MSNs) platform was developed and investigated for specific co-delivery of the paclitaxel (PTX) and gemcitabine (Gem) to cancer cells and preventing their side effects during the treatment process. First, MSNs were synthesized and then coated with as-prepared pH-, and thermo-sensitive niosomes to produce L-MSNs. For this aim, Dipalmitoylphosphatidylcholine (DPPC) was used to create thermo-sensitivity, and 1, 2-Distearoyl-sn-glycerol-3-phosphoethanolamine -Citraconic Anhydride-Polyethylene Glycol (DSPE-CA-PEG) polymers were prepared and incorporated to the lipid layer for creation of pH-sensitivity. In the next step, trastuzumab as a monoclonal antibody (mAb) was conjugated to the maleimide groups of the 1, 2-Distearoyl-sn-glycerol-3-phosphoethanolamine DSPE-polyethylene glycol (PEG)-maleimide agents in the lipid bilayer via a disulfide bond. Dynamic light scattering (DLS) and zeta potential measurements, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and scanning electron microscopy (SEM) analyses were utilized to characterize the synthesized particles before and after surface modification. The encapsulation efficiency (EE%) and loading efficiency (LE%) of the particles were also evaluated. Additionally, the drug release study and MTT assay were done to evaluate the bioactivity potential of the fabricated platforms. The results of DLS and zeta potential measurements revealed an average size of 200 nm and a neutral zeta potential of about -1 mV for mAb-L-MSNs. Also, the FTIR spectra confirmed the formation of mAb-L-MSNs. Moreover, SEM analysis showed spherical-shaped MSNs with amorphous structure confirmed by XRD analysis, and BET test revealed ∼ 820 m2/g specific surface area and pore about 5 nm in size. The values of EE% and LE% of PTX were 90.3 % and 26.7 %, while these values for GEM were 89.5 % and 38.8 % in the co-loaded form, respectively. The thermo-pH-sensitivity examination showed approximately 500 nm of size increase after the change of pH and temperature from 7.4 and 37˚C to 5 and 42˚C. The release profile showed a pH-, and thermo-dependence manner, which led to about 89 % and 95 % of PTX and GEM released from the co-loaded platform at a pH of 5 and 42 °C while these values were 31.1 % and 32.2 % at pH of 7.4 and 37˚C, respectively. MTT assay data presented that when the mAb-L-co-loaded-MSNs platform containing 250 µg/mL drug was used, about 92 % of cells died in human epidermal receptors (HER2)-positive breast cancer cells (SKBR3), while just about 4 % of HER2-negative normal cells were killed. However, the growth inhibition rate of SKBR3 cells was caused by empty-mAb-L-MSNs, pure PTX and GEM combination were 9 % and 87 %, respectively. Moreover, the half inhibitory concentration (IC50) of the pure PTX, pure GEM, and mAb-coloaded-L-MSNs were 33, 17.6, and 6.5 µg/mL. The synergic effect of co-encapsulation of PTX and GEM in addition to trastuzumab conjugated L-MSNs was confirmed by a combinational index (CI) of 0.34. Therefore, this strategy leads to specific targeted drug delivery to cancer cells using a key-lock interaction between the trastuzumab and HER-2 receptors on the cancer cell membrane which stimuli the endocytosis of the particles to the cells followed by the destruction of the lipid layer in the acidic pH and the temperature of the lysosome, leading to enhanced release of PTX and GEM (pH of 5 and 42˚C). So, this platform can be considered a suitable carrier for cancer treatment.

Microfluidic fabricated bisdemethoxycurcumin thermosensitive liposome with enhanced antitumor effect

Bisdemethoxycurcumin (BDMC) is the main active ingredient that is isolated from Zingiberaceae plants, wherein it has excellent anti-tumor effects. However, insolubility in water limits its clinical application. Herein, we reported a microfluidic chip device that can load BDMC into the lipid bilayer to form BDMC thermosensitive liposome (BDMC TSL). The natural active ingredient glycyrrhizin was selected as the surfactant to improve solubility of BDMC. Particles of BDMC TSL had small size, homogenous size distribution, and enhanced cultimulative release in vitro. The anti-tumor effect of BDMC TSL on human hepatocellular carcinomas was investigated via 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, live/dead staining, and flowcytometry. These results showed that the formulated liposome had a strong cancer cell inhibitory, and presented a dose-dependent inhibitory effect on migration. Further mechanistic studies showed that BDMC TSL combined with mild local hyperthermia could significantly upregulate B cell lymphoma 2 associated X protein levels and decrease B cell lymphoma 2 protein levels, thereby inducing cell apoptosis. The BDMC TSL that was fabricated via microfluidic device were decomposed under mild local hyperthermia, which could beneficially enhance the anti-tumor effect of raw insoluble materials and promote translation of liposome.

Pharmacokinetic behaviors of soft nanoparticulate formulations of chemotherapeutics

Chemotherapeutic treatment with conventional drug formulations pose numerous challenges, such as poor solubility, high cytotoxicity and serious off-target side effects, low bioavailability, and ultimately subtherapeutic tumoral concentration leading to poor therapeutic outcomes. In the field of Nanomedicine, advances in nanotechnology have been applied with great success to design and develop novel nanoparticle-based formulations for the treatment of various types of cancer. The approval of the first nanomedicine, Doxil® (liposomal doxorubicin) in 1995, paved the path for further development for various types of novel delivery platforms. Several different types of nanoparticles, especially organic (soft) nanoparticles (liposomes, polymeric micelles, and albumin-bound nanoparticles), have been developed and approved for several anticancer drugs. Nanoparticulate drug delivery platform have facilitated to overcome of these challenges and offered key advantages of improved bioavailability, higher intra-tumoral concentration of the drug, reduced toxicity, and improved efficacy. This review introduces various commonly used nanoparticulate systems in biomedical research and their pharmacokinetic (PK) attributes, then focuses on the various physicochemical and physiological factors affecting the in vivo disposition of chemotherapeutic agents encapsulated in nanoparticles in recent years. Further, it provides a review of the current landscape of soft nanoparticulate formulations for the two most widely investigated anticancer drugs, paclitaxel, and doxorubicin, that are either approved or under investigation. Formulation details, PK profiles, and therapeutic outcomes of these novel strategies have been discussed individually and in comparison, to traditional formulations. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Innovative nanotheranostics: Smart nanoparticles based approach to overcome breast cancer stem cells mediated chemo- and radioresistances

The alarming increase in the number of breast cancer patients worldwide and the increasing death rate indicate that the traditional and current medicines are insufficient to fight against it. The onset of chemo- and radioresistances and cancer stem cell-based recurrence make this problem harder, and this hour needs a novel treatment approach. Competent nanoparticle-based accurate drug delivery and cancer nanotheranostics like photothermal therapy, photodynamic therapy, chemodynamic therapy, and sonodynamic therapy can be the key to solving this problem due to their unique characteristics. These innovative formulations can be a better cargo with fewer side effects than the standard chemotherapy and can eliminate the stability problems associated with cancer immunotherapy. The nanotheranostic systems can kill the tumor cells and the resistant breast cancer stem cells by novel mechanisms like local hyperthermia and reactive oxygen species and prevent tumor recurrence. These theranostic systems can also combine with chemotherapy or immunotherapy approaches. These combining approaches can be the future of anticancer therapy, especially to overcome the breast cancer stem cells mediated chemo- and radioresistances. This review paper discusses several novel theranostic systems and smart nanoparticles, their mechanism of action, and their modifications with time. It explains their relevance and market scope in the current era. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Breaking the niche: multidimensional nanotherapeutics for tumor microenvironment modulation

Most of the current antitumor therapeutics were developed targeting the cancer cells only. Unfortunately, in the majority of tumors, this single-dimensional therapy is found to be ineffective. Advanced research has shown that cancer is a multicellular disorder. The tumor microenvironment (TME), which is made by a complex network of the bulk tumor cells and other supporting cells, plays a crucial role in tumor progression. Understanding the importance of the TME in tumor growth, different treatment modalities have been developed targeting these supporting cells. Recent clinical results suggest that simultaneously targeting multiple components of the tumor ecosystem with drug combinations can be highly effective. This type of "multidimensional" therapy has a high potential for cancer treatment. However, tumor-specific delivery of such multi-drug combinations remains a challenge. Nanomedicine could be utilized for the tumor-targeted delivery of such multidimensional therapeutics. In this review, we first give a brief overview of the major components of TME. We then highlight the latest developments in nanoparticle-based combination therapies, where one drug targets cancer cells and other drug targets tumor-supporting components in the TME for a synergistic effect. We include the latest preclinical and clinical studies and discuss innovative nanoparticle-mediated targeting strategies.

Stimuli-responsive vesicles as distributed artificial organelles for bacterial activation

Intercellular communication is a hallmark of living systems. As such, engineering artificial cells that possess this behavior has been at the heart of activities in bottom-up synthetic biology. Communication between artificial and living cells has potential to confer novel capabilities to living organisms that could be exploited in biomedicine and biotechnology. However, most current approaches rely on the exchange of chemical signals that cannot be externally controlled. Here, we report two types of remote-controlled vesicle-based artificial organelles that translate physical inputs into chemical messages that lead to bacterial activation. Upon light or temperature stimulation, artificial cell membranes are activated, releasing signaling molecules that induce protein expression in Escherichia coli. This distributed approach differs from established methods for engineering stimuli-responsive bacteria. Here, artificial cells (as opposed to bacterial cells themselves) are the design unit. Having stimuli-responsive elements compartmentalized in artificial cells has potential applications in therapeutics, tissue engineering, and bioremediation. It will underpin the design of hybrid living/nonliving systems where temporal control over population interactions can be exerted.

Pharmaceutical liposomal delivery—specific considerations of innovation and challenges

Liposomal technology can enhance drug solubility and stability, achieving codelivery for combination therapy, and modulate the in vivo fate (e.g., site-specific distribution and controlled release), thereby improving treatment outcomes.

Multifunctional lipidic nanocarriers for effective therapy of glioblastoma: recent advances in stimuli-responsive, receptor and subcellular targeted approaches

Background

Glioblastoma, or glioblastoma multiforme (GBM), remains a fatal cancer type despite the remarkable progress in understanding the genesis and propagation of the tumor. Current treatment modalities, comprising mainly of surgery followed by adjuvant chemoradiation, are insufficient for improving patients' survival owing to existing hurdles, including the blood–brain barrier (BBB). In contemporary practice, the prospect of long-term survival or cure continues to be a challenge for patients suffering from GBM. This review provides an insight into the drug delivery strategies and the significant efforts made in lipid-based nanoplatform research to circumvent the challenges in optimal drug delivery in GBM.

Area covered

Owing to the unique properties of lipid-based nanoplatforms and advancements in clinical translation, this article describes the application of various stimuli-responsive lipid nanocarriers and tumor subcellular organelle-targeted therapy to give an idea about the strategies that can be applied to enhance site-specific drug delivery for GBM. Furthermore, active targeting of drugs via surface-modified lipid-based nanostructures and recent findings in alternative therapeutic platforms such as gene therapy, immunotherapy, and multimodal therapy have also been overviewed.

Expert opinion

Lipid-based nanoparticles stand out among the other nanocarriers explored for GBM drug delivery, as they support both passive and active drug targeting by crossing/bypassing the BBB at the same time minimizing toxicity and projects better pharmacological parameters. Although these nanocarriers could be a plausible choice for treating GBM, in-depth research is essential to advance neuro-oncology research and enhance outcomes in patients with brain tumors.

Design, Synthesis and Characterization of a Novel Type of Thermo-Responsible Phospholipid Microcapsule-Alginate Composite Hydrogel for Drug Delivery

Liposomes are extensively used in drug delivery, while alginates are widely used in tissue engineering. However, liposomes are usually thermally unstable and drug-leaking when in liquids, while the drug carriers made of alginates show low loading capacities when used for drug delivery. Herein, we developed a type of thermo-responsible liposome-alginate composite hydrogel (TSPMAH) by grafting thermo-responsive liposomes onto alginates by using Ca2+ mediated bonding between the phosphatidic serine (PS) in the liposome membrane and the alginate. The temperature-sensitivity of the liposomes was actualized by using phospholipids comprising dipalmitoylphosphatidylcholine (DPPC) and PS and the liposomes were prepared by a thin-film dispersion method. The TSPMAH was then successfully prepared by bridge-linking the microcapsules onto the alginate hydrogel via PS-Ca2+-Carboxyl-alginate interaction. Characterizations of the TSPMAH were carried out using scanning electron microscopy, transform infrared spectroscopy, and laser scanning confocal microscopy, respectively. Their rheological property was also characterized by using a rheometer. Cytotoxicity evaluations of the TSPMAH showed that the composite hydrogel was biocompatible, safe, and non-toxic. Further, loading and thermos-inducible release of model drugs encapsulated by the TSPMAH as a drug carrier system was also studied by making protamine-siRNA complex-carrying TSPMAH drug carriers. Our results indicated that the TSPMAH described herein has great potentials to be further developed into an intelligent drug delivery system.

Development of functional liposomes by modification of stimuli-responsive materials and their biomedical applications

Liposomes are a promising nanocarrier for drug delivery because of their biocompatibility and the encapsulation capacity of drugs. Liposomes can be functionalized easily by introduction of functional materials such as stimulus-responsive materials. Temperature-responsive liposomes and pH-responsive liposomes are representative stimulus-responsive liposomes that can deliver drugs to locally heated target tissues and intracellular organelles. Here, temperature-responsive liposomes for the selective release of cargo and pH-responsive liposomes for the induction of antigen-specific immunity are overviewed. Temperature-responsive polymer-modified liposomes immediately released drugs in response to heating, which achieved selective drug release at a tumour after topical heating of tumour-bearing mice. Introduction of MR-detectable molecules enabled the tracing of liposome accumulation into target sites to optimize the heating timing. These liposomes can also be combined with magnetic nanoparticles or carbon nanomaterials to attain magnetic field-responsive, electric field-responsive and light-responsive properties to support on-demand drug release or control of biological reactions using these external stimuli. pH-Responsive liposomes were produced by modification of poly(carboxylic acid) derivatives or by pH-responsive amphiphiles. These liposomes delivered antigenic proteins into the cytosol of antigen presenting cells, which induced cross-presentation and antigen-specific cellular immunity. Adjuvant molecules or bioactive polysaccharide-based pH-responsive polymers improved their immunity-inducing effect further, leading to tumour regression in tumour-bearing mice. Precise design and control of the structures of stimulus-responsive materials and combination with functional materials are expected to create novel methodologies to control biological functions and to produce highly potent liposomal drugs that can achieve selective release of bioactive molecules.

Hyperthermia can alter tumor physiology and improve chemo- and radio-therapy efficacy

Hyperthermia has demonstrated clinical success in improving the efficacy of both chemo- and radio-therapy in solid tumors. Pre-clinical and clinical research studies have demonstrated that targeted hyperthermia can increase tumor blood flow and increase the perfused fraction of the tumor in a temperature and time dependent manner. Changes in tumor blood circulation can produce significant physiological changes including enhanced vascular permeability, increased oxygenation, decreased interstitial fluid pressure, and reestablishment of normal physiological pH conditions. These alterations in tumor physiology can positively impact both small molecule and nanomedicine chemotherapy accumulation and distribution within the tumor, as well as the fraction of the tumor susceptible to radiation therapy. Hyperthermia can trigger drug release from thermosensitive formulations and further improve the accumulation, distribution, and efficacy of chemotherapy.

Challenges and pitfalls in the development of liposomal delivery systems for cancer therapy

Despite considerable advances in the application of liposomal drug delivery systems in cancer treatment, the clinical application of liposomal formulations has been limited by many factors. It seems that there is a wide gap between results of experimental studies and clinical application of liposomes. In this review, we discuss barriers which limit the translation of liposomal delivery systems in cancer therapy. The main focus of this review will be on differences between preclinical and clinical studies and potential approaches to overcome the main pitfalls in the clinical application of liposomal delivery systems.