Monoclonal antibody-targeted, temperature-sensitive liposomes: in vivo tumor chemotherapeutics in combination with mild hyperthermia

Effective Use of Euphorbia milii DCM Root Extract Encapsulated by Thermosensitive Immunoliposomes for Targeted Drug Delivery in Prostate Cancer Cells

The delivery of anticancer drugs using nanotechnology is a promising approach aimed at improving the therapeutic efficacy and reducing the toxicity of chemotherapeutic agents. Liposomes were prepared using HSPC: DSPE-PEG-2000: DSPE-PEG2000-maleimide in the ratio of 4:1:0.2 and conjugated with a PSA antibody. Euphorbia milii extract (EME), doxorubicin (Dox), and docetaxel (Doc) encapsulated in temperature-sensitive immunoliposomes were investigated for their activities against the prostate cancer LNCap and DU145 cell lines. Organic extracts of EME leaves, roots, and stems were screened against both cell lines, inhibiting more than 50% of cell culture at concentrations of 10 μg/mL. The immunoliposomes incorporating the EME and docetaxel were active against the LNCap cells when exposed to heat at 39-40 °C. The liposomes not exposed to heat were inactive against the LNCap cells. The developed heat-sensitive immunoliposomes used for the delivery of both the EME and chemotherapeutic agents was able to successfully release the entrapped contents upon heat exposure above the phase transition temperature of the liposome membrane. The heat-sensitive immunoliposomes conjugated with a PSA antibody encapsulated the extract successfully and showed better cell antiproliferation efficacy against the prostate cancer cell lines in the presence of heat.

Application and Method of Surface Plasmon Resonance Technology in the Preparation and Characterization of Biomedical Nanoparticle Materials

Surface Plasmon Resonance (SPR) technology, as a powerful analytical tool, plays a crucial role in the preparation, performance evaluation, and biomedical applications of nanoparticles due to its real-time, label-free, and highly sensitive detection capabilities. In the nanoparticle preparation process, SPR technology can monitor synthesis reactions and surface modifications in real-time, optimizing preparation techniques and conditions. SPR enables precise measurement of interactions between nanoparticles and biomolecules, including binding affinities and kinetic parameters, thereby assessing nanoparticle performance. In biomedical applications, SPR technology is extensively used in the study of drug delivery systems, biomarker detection for disease diagnosis, and nanoparticle-biomolecule interactions. This paper reviews the latest advancements in SPR technology for nanoparticle preparation, performance evaluation, and biomedical applications, discussing its advantages and challenges in biomedical applications, and forecasting future development directions.

Physicochemical Stimulus-Responsive Systems Targeted with Antibody Derivatives

The application of monoclonal antibodies and antibody fragments with the advent of recombinant antibody technology has made notable progress in clinical trials to provide a regulated drug release and extra targeting to the special conditions in the function site. Modification of antibodies has facilitated using mAbs and antibody fragments in numerous models of therapeutic and detection utilizations, such as stimuliresponsive systems. Antibodies and antibody derivatives conjugated with diverse stimuliresponsive materials have been constructed for drug delivery in response to a wide range of endogenous (electric, magnetic, light, radiation, ultrasound) and exogenous (temperature, pH, redox potential, enzymes) stimuli. In this report, we highlighted the recent progress on antibody-conjugated stimuli-responsive and dual/multi-responsive systems that affect modern medicine by improving a multitude of diagnostic and treatment strategies.

Surface modification strategies in translocating nano-vesicles across different barriers and the role of bio-vesicles in improving anticancer therapy

Nanovesicles and bio-vesicles (BVs) have emerged as promising tools to achieve targeted cancer therapy due to their ability to overcome many of the key challenges currently being faced with conventional chemotherapy. These challenges include the diverse and often complex pathophysiology involving the progression of cancer, as well as the various biological barriers that circumvent therapeutic molecules reaching their target site in optimum concentration. The scientific evidence suggests that surface-functionalized nanovesicles and BVs camouflaged nano-carriers (NCs) both can bypass the established biological barriers and facilitate fourth-generation targeting for the improved regimen of treatment. In this review, we intend to emphasize the role of surface-functionalized nanovesicles and BVs camouflaged NCs through various approaches that lead to an improved internalization to achieve improved and targeted oncotherapy. We have explored various strategies that have been employed to surface-functionalize and biologically modify these vesicles, including the use of biomolecule functionalized target ligands such as peptides, antibodies, and aptamers, as well as the targeting of specific receptors on cancer cells. Further, the utility of BVs, which are made from the membranes of cells such as mesenchymal stem cells (MSCs), white blood cells (WBCs), red blood cells (RBCs), platelets (PLTs) as well as cancer cells also been investigated. Lastly, we have discussed the translational challenges and limitations that these NCs can encounter and still need to be overcome in order to fully realize the potential of nanovesicles and BVs for targeted cancer therapy. The fundamental challenges that currently prevent successful cancer therapy and the necessity of novel delivery systems are in the offing.

Thermal/ultrasound-triggered release of liposomes loaded with Ganoderma applanatum polysaccharide from microbubbles for enhanced tumour ablation

The effectiveness of thermal ablation for the treatment of liver tumours is limited by the risk of incomplete ablation, which can result in residual tumours. Herein, an enhancement strategy is proposed based on the controlled release of Ganoderma applanatum polysaccharide (GAP) liposome-microbubble complexes (GLMCs) via ultrasound (US)-targeted microbubble destruction (UTMD) and sublethal hyperthermic (SH) field. GLMCs were prepared by conjugating GAP liposomes onto the surface of microbubbles via biotin-avidin linkage. In vitro, UTMD promotes the cellular uptake of liposomes and leads to apoptosis of M2-like macrophages. Secretion of arginase-1 (Arg-1) and transforming growth factor-beta (TGF-β) by M2-like macrophages decreased. In vivo, restriction of tumour volume was observed in rabbit VX2 liver tumours after treatment with GLMCs via UTMD in GLMCs + SH + US group. The expression levels of CD68 and CD163, as markers of tumour-associated macrophages (TAMs) in the GLMCs + SH + US group were reduced in liver tumour tissue. Decreased Arg-1, TGF-β, Ki67, and CD31 factors related to tumour cell proliferation and angiogenesis was evident on histological analysis. In conclusion, thermal/US-triggered drug release from GLMCs suppressed rabbit VX2 liver tumour growth in the SH field by inhibiting TAMs, which represents a potential approach to improve the effectiveness of thermal ablation.

Functionalized liposomes for targeted breast cancer drug delivery

Despite the exceptional progress in breast cancer pathogenesis, prognosis, diagnosis, and treatment strategies, it remains a prominent cause of female mortality worldwide. Additionally, although chemotherapies are effective, they are associated with critical limitations, most notably their lack of specificity resulting in systemic toxicity and the eventual development of multi-drug resistance (MDR) cancer cells. Liposomes have proven to be an invaluable drug delivery system but of the multitudes of liposomal systems developed every year only a few have been approved for clinical use, none of which employ active targeting. In this review, we summarize the most recent strategies in development for actively targeted liposomal drug delivery systems for surface, transmembrane and internal cell receptors, enzymes, direct cell targeting and dual-targeting of breast cancer and breast cancer-associated cells, e.g., cancer stem cells, cells associated with the tumor microenvironment, etc.

Nanocarrier design–function relationship: The prodigious role of properties in regulating biocompatibility for drug delivery applications

The concept of drug delivery systems as a magic bullet for the delivery of bioactive compounds has emerged as a promising approach in the treatment of different diseases with significant advantages over the limitations of traditional methods. While nanocarrier-based drug delivery systems are the main advocates of drug uptake because they offer several advantages including reduced non-specific biodistribution, improved accumulation, and enhanced therapeutic efficiency; their safety and biocompatibility within cellular/tissue systems are therefore important for achieving the desired effect. The underlying power of "design-interplay chemistry" in modulating the properties and biocompatibility at the nanoscale level will direct the interaction with their immediate surrounding. Apart from improving the existing nanoparticle physicochemical properties, the balancing of the hosts' blood components interaction holds the prospect of conferring newer functions altogether. So far, this concept has been remarkable in achieving many fascinating feats in addressing many challenges in nanomedicine such as immune responses, inflammation, biospecific targeting and treatment, and so on. This review, therefore, provides a diverse account of the recent advances in the fabrication of biocompatible nano-drug delivery platforms for chemotherapeutic applications, as well as combination therapy, theragnostic, and other diseases that are of interest to scientists in the pharmaceutical industries. Thus, careful consideration of the "property of choice" would be an ideal way to realize specific functions from a set of delivery platforms. Looking ahead, there is an enormous prospect for nanoparticle properties in regulating biocompatibility.

Cisplatin-Loaded Thermosensitive Liposomes Functionalized with Hyaluronic Acid: Cytotoxicity and In Vivo Acute Toxicity Evaluation

Cisplatin (CDDP) is a potent antitumor drug used in first-line chemotherapy against several solid tumors, including breast cancer. However, toxicities and drug resistance limit its clinical application. Thermosensitive liposome (TSL) functionalized with hyaluronic acid (HA) containing cisplatin (TSL-CDDP-HA) was developed by our research group aiming to promote the release of CDDP in the tumor region under hyperthermia conditions, as well as to decrease toxicity. Thus, this study aimed to evaluate this new formulation (HA-coated TSL-CDDP) concerning in vitro behavior and in vivo toxicity compared to non-coated TSL-CDDP and free CDDP. Cytotoxicity assays and nuclear morphology were carried out against triple-negative breast cancer cells (MDA-MB-231), while an in vivo toxicity study was performed using healthy Swiss mice. The results showed an increase (around 3-fold) in cytotoxicity of the cationic formulation (non-coated TSL-CDDP) compared to free CDDP. On the other hand, TSL-CDDP treatment induced the appearance of 2.5-fold more senescent cells with alteration of nuclear morphology than the free drug after hyperthermia condition. Furthermore, the association of liposomal formulations treatment with hyperthermia increased the percentage of apoptotic cells compared to those without heating. The percentage of apoptotic cells was 1.7-fold higher for TSL-CDDP-HA than for TSL-CDDP. For the in vivo toxicity data, the TSL-CDDP treatment was also toxic to healthy cells, inducing nephrotoxicity with a significant increase in urea levels compared to the saline control group (73.1 ± 2.4 vs. 49.2 ± 2.8 mg/mL). On the other hand, the HA-coated TSL-CDDP eliminated the damages related to the use of CDDP since the animals did not show changes in hematological and biochemical examinations and histological analyses. Thus, data suggest that this new formulation is a potential candidate for the intravenous therapy of solid tumors.

Peptide-functionalised magnetic silk nanoparticles produced by a swirl mixer for enhanced anticancer activity of ASC-J9

Silk fibroin is an FDA approved biopolymer for clinical applications with great potential in nanomedicine. However, silk-based nanoformulations are still facing several challenges in processing and drug delivery efficiency (such as reproducibility and targetability), especially in cancer therapy. To address these challenges, robust and controllable production methods are required for generating nanocarriers with desired properties. This study aimed to develop a novel method for the production of peptide-functionalized magnetic silk nanoparticles with higher selectivity for cancer cells for targeted delivery of the hydrophobic anticancer agent ASC-J9. A new microfluidic device with a swirl mixer was designed to fabricate magnetic silk nanoparticles (MSNP) with desired size and narrow size distribution. The surface of MSNPs was functionalized with a cationic amphiphilic anticancer peptide, G(IIKK)3I-NH2 (G3), to enhance their selectivity towards cancer cells. The G3-MSNPs increased the cellular uptake and anticancer activity of G3 in HCT 116 colorectal cancer cells compared to free G3. Moreover, the G3-MSNPs exhibited considerably higher cellular uptake and cytotoxicity in HCT 116 colorectal cancer cells compared to normal cells (HDFs). Encapsulating ASC-J9 in G3-MSNPs resulted in augmented anticancer activity compared to free ASC-J9 and non-functionalized ASC-J9 loaded MSNPs within its biological half-life. Hence, functionalizing MSNPs with G3 enabled targeted delivery of ASC-J9 to cancer cells and enhanced its anticancer effect. Functionalization of nanoparticles with anticancer peptides could be regarded as a new strategy for targeted delivery and enhanced efficiency of anticancer drugs. Furthermore, the microfluidic device introduced in this paper offers a robust and reproducible method for fabrication of small sized homogenous nanoparticles.

Functionalization of Nanoparticulate Drug Delivery Systems and Its Influence in Cancer Therapy

Research into the application of nanocarriers in the delivery of cancer-fighting drugs has been a promising research area for decades. On the other hand, their cytotoxic effects on cells, low uptake efficiency, and therapeutic resistance have limited their therapeutic use. However, the urgency of pressing healthcare needs has resulted in the functionalization of nanoparticles' (NPs) physicochemical properties to improve clinical outcomes of new, old, and repurposed drugs. This article reviews recent research on methods for targeting functionalized nanoparticles to the tumor microenvironment (TME). Additionally, the use of relevant engineering techniques for surface functionalization of nanocarriers (liposomes, dendrimers, and mesoporous silica) and their critical roles in overcoming the current limitations in cancer therapy-targeting ligands used for targeted delivery, stimuli strategies, and multifunctional nanoparticles-were all reviewed. The limitations and future perspectives of functionalized nanoparticles were also finally discussed. Using relevant keywords, published scientific literature from all credible sources was retrieved. A quick search of the literature yielded almost 400 publications. The subject matter of this review was addressed adequately using an inclusion/exclusion criterion. The content of this review provides a reasonable basis for further studies to fully exploit the potential of these nanoparticles in cancer therapy.

Can two-step ablation combined with chemotherapeutic liposomes achieve better outcome than traditional RF ablation? A solid tumor animal study

Objectives: To determine whether two-step ablation using sequential low and high temperature heating can achieve improved outcomes in animal tumor models when combined with chemotherapeutic liposomes (LP). Materials and methods: Balb/c mice bearing 4T1 tumor received paclitaxel-loaded liposomes followed 24 h later by either traditional RFA (70 °C, 5 min) or a low temperature RFA (45 °C, 5 min), or two-step RFA (45 °C 2 min + 70 °C 3 min). Intratumoral drug accumulation and bio-distribution in major organs were evaluated. Periablational drug penetration was evaluated by pathologic staining and the intratumoral interstitial fluid pressure (IFP) was measured directly. For long-term outcomes, mice bearing 4T1 or H22 tumors were randomized into five groups (n = 8 per group): control (no treatment), RFA alone, LP + RFA (45 °C), LP + RFA (70 °C) and LP + RFA (45 + 70 °C). End-point survivals were compared among the different groups. Results: The greater intratumoral drug accumulation (3.35 ± 0.32 vs. 3.79 ± 0.29 × 108 phot/cm2/s at 24 h, p = 0.09), deeper periablational drug penetration (45.7 ± 5.0 vs. 1.6 ± 0.5, p < 0.001), and reduced off-target drug deposition in major organs (liver 96.1 ± 31.6 vs. 47.4 ± 1.5 × 106 phot/cm2/s, p < 0.001) were found when combined with RFA (45 °C) compared to drug alone. For long-term outcomes, 4T1 tumor growth rates for LP + two-step RFA (45 + 70 °C) were significantly slower than those of LP + RFA (70 °C), LP + RFA (45 °C), and RFA alone (P < 0.01 for all comparisons). End point survival for LP + RFA (45 + 70 °C) was also longer than that for LP + RFA (70 °C) (median 16 vs. 10 days, p = 0.003) or LP + RFA 45 °C (11 days, p = 0.009) and RFA alone (8.3 days, p < 0.001) in 4T1 tumor models. The intratumoral IFP after RFA (45 °C) was significantly lower than baseline RFA (3.3 ± 0.8 vs. 19.2 ± 3.1 mmHg, p < 0.001), but was not measurable after RFA (70 °C). Conclusions: A two-step ablation combined with chemotherapeutic liposomes can achieve better survival benefit compared to traditional RFA in animal models.

Liposomes, new carriers for delivery of genes and anticancer drugs: a systematic review

Today, nanoscience has grown and developed in various fields of medicine and treatment, including cancer treatment. Currently, the existing treatments, including chemotherapy and radiotherapy, cause side effects that are unpleasant to the patient. Due to the fact that anticancer drugs cause severe and widespread side effects, liposomes are considered as new drug carriers to minimize the untimely destruction of the drug when it is delivered to the target tissue and to prevent the side effects of toxic drugs. This systematic review study examined the importance of using liposomes as new drug carriers for the delivery of genes and anticancer drugs. The articles published in English in the databases of Google scholar, WoS, PubMed, Embase, Scopus and science direct were reviewed. According to the results of this study, a new targeted nanosystem has been used for loading and delivering anticancer drugs, genes and controlled drug release which has a significant therapeutic effect compared to the same amount of free drug. In general, liposomal systems have been considered because of their capability in preserving the effect of the drug along with reducing the side effects and toxicity of the drug, especially in the case of anticancer drugs. Accumulation of the drug in a target tissue which results in a reduction of the drug entry into other tissues is the main reason for reducing the side effects of these drugs.

Obstacles and opportunities in a forward vision for cancer nanomedicine

Cancer nanomedicines were initially envisioned as magic bullets, travelling through the circulation to target tumours while sparing healthy tissues the toxicity of classic chemotherapy. While a limited number of nanomedicine therapies have resulted, the disappointing news is that major obstacles were overlooked in the nanoparticle's journey. However, some of these challenges may be turned into opportunities. Here, we discuss biological barriers to cancer nanomedicines and elaborate on two directions that the field is currently exploring to meet its initial expectations. The first strategy entails re-engineering cancer nanomedicines to prevent undesired interactions en route to the tumour. The second aims instead to leverage these obstacles into out-of-the-box diagnostic and therapeutic applications of nanomedicines, for cancer and beyond. Both paths require, among other developments, a deeper understanding of nano-bio interactions. We offer a forward look at how classic cancer nanomedicine may overcome its limitations while contributing to other areas of research.

Application of Non-Viral Vectors in Drug Delivery and Gene Therapy

Vectors and carriers play an indispensable role in gene therapy and drug delivery. Non-viral vectors are widely developed and applied in clinical practice due to their low immunogenicity, good biocompatibility, easy synthesis and modification, and low cost of production. This review summarized a variety of non-viral vectors and carriers including polymers, liposomes, gold nanoparticles, mesoporous silica nanoparticles and carbon nanotubes from the aspects of physicochemical characteristics, synthesis methods, functional modifications, and research applications. Notably, non-viral vectors can enhance the absorption of cargos, prolong the circulation time, improve therapeutic effects, and provide targeted delivery. Additional studies focused on recent innovation of novel synthesis techniques for vector materials. We also elaborated on the problems and future research directions in the development of non-viral vectors, which provided a theoretical basis for their broad applications.

Surface Biomodification of Liposomes and Polymersomes for Efficient Targeted Drug Delivery

Chemotherapy has seen great progress in the development of performant treatment strategies. Nanovesicles such as liposomes and polymersomes demonstrated great potential in cancer therapy. However, these nanocarriers deliver their content passively, which faces a lot of constraints during blood circulation. The main challenge resides in degradation and random delivery to normal tissues. Hence, targeting drug delivery using specific molecules (such as antibodies) grafted over the surface of these nanocarriers came as the answer to overcome many problems faced before. The advantage of using antibodies is their antigen/antibody recognition, which provides a high level of specificity to reach treatment targets. This review discusses the many techniques of nanocarrier functionalization with antibodies. The aim is to recognize the various approaches by describing their advantages and deficiencies to create the most suitable drug delivery platform. Some methods are more suitable for other applications rather than drug delivery, which can explain the low success of some proposed targeted nanocarriers. In here, a critical analysis of how every method could impact the recognition and targeting capacity of some nanocarriers (liposomes and polymersomes) is discussed to make future research more impactful and advance the field of biomedicine further.

Multi-stimuli-responsive, liposome-crosslinked poly(ethylene glycol) hydrogels for drug delivery

The development of hybrid hydrogels has been of great interest over recent decades, especially in the field of biomaterials. Such hydrogels provide various opportunities in tissue engineering, drug delivery, and regenerative medicine due to their ability to mimic cellular environments, sequester and release therapeutic agents, and respond to stimuli. Herein we report the synthesis and characterization of an injectable poly(ethylene glycol) hydrogel crosslinked via thiol-maleimide reactions and containing both chemically crosslinked temperature-sensitive liposomes (TSLs) and matrix metalloproteinase-sensitive peptide crosslinks. Rheological studies demonstrate that the hydrogel is mechanically stable and can be synthesized to achieve a range of physically applicable moduli. Experiments characterizing the in situ drug delivery and degradation of these materials indicate that the TSL gel responds to both thermal and enzymatic stimuli in a local environment. Doxorubicin, a widely used anticancer drug, was loaded in the TSLs with a high encapsulation efficiency and the subsequent release was temperature dependent. Finally, TSLs did not compromise viability and proliferation of human and murine fibroblasts, supporting the use of these hydrogel-linked liposomes as a thermo-responsive drug carrier for controlled release.

Surface Plasmon Resonance as a Characterization Tool for Lipid Nanoparticles Used in Drug Delivery

The development of drug carriers based in lipid nanoparticles (LNPs) aims toward the synthesis of non-toxic multifunctional nanovehicles that can bypass the immune system and allow specific site targeting, controlled release and complete degradation of the carrier components. Among label free techniques, Surface Plasmon Resonance (SPR) biosensing is a versatile tool to study LNPs in the field of nanotherapeutics research. SPR, widely used for the analysis of molecular interactions, is based on the immobilization of one of the interacting partners to the sensor surface, which can be easily achieved in the case of LNPs by hydrophobic attachment onto commercial lipid- capture sensor chips. In the last years SPR technology has emerged as an interesting strategy for studying molecular aspects of drug delivery that determines the efficacy of the nanotherapeutical such as LNPs' interactions with biological targets, with serum proteins and with tumor extracelullar matrix. Moreover, SPR has contributed to the obtention and characterization of LNPs, gathering information about the interplay between components of the formulations, their response to organic molecules and, more recently, the quantification and molecular characterization of exosomes. By the combination of available sensor platforms, assay quickness and straight forward platform adaptation for new carrier systems, SPR is becoming a high throughput technique for LNPs' characterization and analysis.

PEG Linker Length Strongly Affects Tumor Cell Killing by PEGylated Carbonic Anhydrase Inhibitors in Hypoxic Carcinomas Expressing Carbonic Anhydrase IX

Hypoxic tumors overexpress membrane-bound isozymes of carbonic anhydrase (CA) CA IX and CA XII, which play key roles in tumor pH homeostasis under hypoxia. Selective inhibition of these CA isozymes has the potential to generate pH imbalances that can lead to tumor cell death. Since these isozymes are dimeric, we designed a series of bifunctional PEGylated CA inhibitors (CAIs) through the attachment of our preoptimized CAI warhead 1,3,4-thiadiazole-2-sulfonamide to polyethylene glycol (PEG) backbones with lengths ranging from 1 KDa to 20 KDa via a succinyl linker. A detailed structure−thermal properties and structure–biological activity relationship study was conducted via differential scanning calorimetry (DSC) and via viability testing in 2D and 3D (tumor spheroids) cancer cell models, either CA IX positive (HT-29 colon cancer, MDA-MB 231 breast cancer, and SKOV-3 ovarian cancer) or CA IX negative (NCI-H23 lung cancer). We identified PEGylated CAIs DTP1K 28, DTP2K 23, and DTP3.4K 29, bearing short and medium PEG backbones, as the most efficient conjugates under both normoxic and hypoxic conditions, and in the tumor spheroid models. PEGylated CAIs did not affect the cell viability of CA IX-negative NCI-H23 tumor spheroids, thus confirming a CA IX-mediated cell killing for these potential anticancer agents.

Encapsulated doxorubicin crystals influence lysolipid temperature-sensitive liposomes release and therapeutic efficacy in vitro and in vivo

Doxorubicin (DOX)-loaded lysolipid temperature-sensitive liposomes (LTSLs) are a promising stimuli-responsive drug delivery system that rapidly releases DOX in response to mild hyperthermia (HT). This study investigates the influence of loaded DOX crystals on the thermosensitivity of LTSLs and their therapeutic efficacy in vitro and in vivo. The properties of DOX crystals were manipulated using different remote loading methods (namely (NH₄)₂SO₄, NH₄-EDTA and MnSO₄) and varying the lipid:DOX weight ratio during the loading step. Our results demonstrated that (NH₄)₂SO₄ or NH₄-EDTA remote loading methods had a comparable encapsulation efficiency (EE%) into LTSLs in contrast to the low DOX EE% obtained using the metal complexation method. Cryogenic transmission electron microscopy (cryo-TEM) revealed key differences in the nature of DOX crystals formed inside LTSLs based on the loading buffer or/and the lipid:DOX ratio used, resulting in different DOX release profiles in response to mild HT. The in vitro assessment of DOX release/uptake in CT26 and PC-3 cells revealed that the use of a high lipid:DOX ratio exhibited a fast and controlled release profile in combination with mild HT, which correlated well with their cytotoxicity studies. Similarly, in vivo DOX release, tumour growth inhibition and mice survival rates were influenced by the physicochemical properties of LTSLs payload. This study demonstrates, for the first time, that the characteristics of DOX crystals loaded into LTSLs, and their conformational rearrangement during HT, are important factors that impact the TSLs performance in vivo.

An acoustic/thermo-responsive hybrid system for advanced doxorubicin delivery in tumor treatment

The efficiency of drug delivery and bioavailability to tumor cells are crucial for effective cancer chemotherapy. Herein, a doxorubicin (DOX) encapsulated lysolipid-based thermosensitive liposome decorated with cRGD peptide (RTSL) is conjugated on the surface of an IR780-loaded microbubble (IMB) to synthesize RTSL-IMBs. Sequentially taking advantage of acoustic-assisted early extravasation and thermo-triggered interstitium ultrafast drug release, RTSL-IMBs combine with ultrasound (US) and laser irradiation can advance drug delivery and bioavailability. In vitro experiments demonstrate that RTSL-IMBs associated with a two-step protocol (subsequently US irradiation for 1 min and laser irradiation for 5 min) can dramatically enhance the cellular uptake and bioavailability of DOX. In vivo fluorescence imaging studies reveal that the combination of RTSL-IMBs and US shows a 2.8-fold intratumoral drug accumulation increase at 0.5 h post-injection, while it will take 48 h to reach the same level of intratumoral drug accumulation for the RTSL-IMB group alone. Interestingly, the following localized application of a laser can further increase drug accumulation and slow tumor clearance. Histological analysis demonstrates that the combinational RTSL-IMBs, US and laser significantly improve the drug penetration distance and delivery efficiency in the tumor core. In this study, the acoustic/thermo-responsive hybrid system shows potential for advancing DOX chemotherapy in breast cancer cell MCF-7 xenograft nude mice.

Liposomes modified with bio-substances for cancer treatment

In recent years, liposomes have been used in the field of biomedicine and have achieved many significant results.

Updates on the use of liposomes for active tumor targeting in cancer therapy

In the development of cancer chemotherapy, besides the discovery of new anticancer drugs, a variety of nanocarrier systems for the delivery of previously developed and new chemotherapeutic drugs have currently been explored. Liposome is one of the most studied nanocarrier systems because of its biodegradability, simple preparation method, high efficacy and low toxicity. To make the best use of this vehicle, a number of multifunctionalized liposomal formulations have been investigated. The objective of this review is to summarize the current development of novel active targeting liposomal formulations, and to give insight into the challenges and future direction of the field. The recent studies in active targeting liposomes suggest the great potential of precise targeted anticancer drug delivery in cancer therapeutics.

Selective Liposomal Transport through Blood Brain Barrier Disruption in Ischemic Stroke Reveals Two Distinct Therapeutic Opportunities

The development of effective therapies for stroke continues to face repeated translational failures. Brain endothelial cells form paracellular and transcellular barriers to many blood-borne therapies, and the development of efficient delivery strategies is highly warranted. Here, in a mouse model of stroke, we show selective recruitment of clinically used liposomes into the ischemic brain that correlates with biphasic blood brain barrier (BBB) breakdown. Intravenous administration of liposomes into mice exposed to transient middle cerebral artery occlusion took place at early (0.5 and 4 h) and delayed (24 and 48 h) time points, covering different phases of BBB disruption after stroke. Using a combination of in vivo real-time imaging and histological analysis we show that selective liposomal brain accumulation coincides with biphasic enhancement in transcellular transport followed by a delayed impairment to the paracellular barrier. This process precedes neurological damage in the acute phase and maintains long-term liposomal colocalization within the neurovascular unit, which could have great potential for neuroprotection. Levels of liposomal uptake by glial cells are similarly selectively enhanced in the ischemic region late after experimental stroke (2-3 days), highlighting their potential for blocking delayed inflammatory responses or shifting the polarization of microglia/macrophages toward brain repair. These findings demonstrate the capability of liposomes to maximize selective translocation into the brain after stroke and identify two windows for therapeutic manipulation. This emphasizes the benefits of selective drug delivery for efficient tailoring of stroke treatments.

Dual-Functional Liposomes with Carbonic Anhydrase IX Antibody and BR2 Peptide Modification Effectively Improve Intracellular Delivery of Cantharidin to Treat Orthotopic Hepatocellular Carcinoma Mice

Liposomal nanotechnology has a great potential to overcome the current major problems of chemotherapy. However, the lack of penetrability and targetability retards the successful delivery of liposomal carriers. Previously, we showed that BR2 peptide modification endowed cantharidin-loaded liposomes with intracellular penetration that enhanced the drug cytotoxic effects. Here, we aimed to improve the targeting delivery of drugs into cancer cells via highly expressed carbonic anhydrase IX (CA IX) receptors by modifying our previous catharidin-loaded BR2-liposomes with anti-CA IX antibody. A higher cellular uptake of dual-functional liposomes (DF-Lp) than other treatments was observed. Induction of CA IX over-expressing resulted in a higher cellular binding of DF-Lp; subsequently, blocking with excess antibodies resulted in a decreased cancer-cell association, indicating a specific targeting property of our liposomes towards CA IX expressed cells. After 3h tracking, most of the liposomes were located around the nucleus which confirmed the involvement of targeting intracellular delivery. Cantharidin loaded DF-Lp exhibited enhanced cytotoxicity in vitro and was most effective in controlling tumor growth in vivo in an orthotopic hepatocellular carcinoma model compared to other groups. Collectively, our results presented the advantage of the BR2 peptide and CA IX antibody combination to elevate the therapeutic potential of cantharidin loaded DF-liposomes.

A novel tumor-targeted thermosensitive liposomal cerasome used for thermally controlled drug release

Drug carriers with tumor targeting and controlled release have strong prospects for application in safe and efficient chemotherapy. Among various carriers, liposomes have good biocompatibility and can enhance the uptake of drugs by cancer cells. However, traditional liposomes have no specific targeting to cancer cells and are prone to insufficient stability, causing early leakage of the drug. Accordingly, organic-inorganic hybrid phospholipid and thermosensitive phospholipid are deliberately introduced into a liposome system to enhance the morphological and structural stability of the liposomes while realizing thermally controlled drug release. Furthermore, modification with a targeting ligand (WSG-peptide) can endow liposomes with active targeting to ovarian carcinoma cells. First, WSG-peptide was grafted onto the hydrophilic terminal of phospholipid molecules, and the organic-inorganic hybrid cerasome-forming lipid (CFL) was synthesized via a two-step chemical reaction. Then, the WSG-grafted thermosensitive liposomal cerasome (c-LIP-WSG) was prepared by thin-film hydration method. The results showed that the c-LIP-WSG had excellent structural stability both in storage and in a simulated circulation environment. In vitro drug release confirmed that the liposomes exhibited thermally controlled release. Cell uptake experiments and living fluorescence imaging of SKOV-3 tumor-bearing nude mice confirmed that the WSG-peptide modified liposomes were provided with specific targeting properties for ovarian carcinoma.

Glioma-targeted dual functionalized thermosensitive Ferri-liposomes for drug delivery through an in vitro blood-brain barrier

To date, the delivery of therapeutic agents for malignant brain tumors (such as glioblastoma multiforme (GBM)) remains a significant obstacle due to the existence of the blood-brain barrier (BBB). A multitude of delivery systems (hydrogels, micelles, polymeric nanoparticles, etc.) have been proposed, yet many of them exhibit limited tumor-specific inhibition effects. Herein, a drug-encapsulated dual-functionalized thermosensitive liposomal system (DOX@P1NS/TNC-FeLP) was developed for targeted delivery across the BBB. Specifically, a GBM-specific cell-penetrating peptide (P1NS) and an anti-GBM antibody (TN-C) were conjugated onto the liposome surface for targeted delivery. In addition, superparamagnetic iron oxide nanoparticles (SPIONs) and doxorubicin (DOX) were co-loaded inside the liposomes to achieve thermo-triggered drug release when applying an alternating magnetic field (AMF). Results demonstrated that P1NS/TNC-FeLPs readily transported across an in vitro BBB model and displayed a thermo-responsive and GBM-specific cellular uptake as well as drug release profile. Additionally, results from immunofluorescent (IF) staining and RT-qPCR further demonstrated that DOX@P1NS/TNC-FeLPs specifically entered U-87 human GBM cells and suppressed tumor cell proliferation without causing any significant impact on healthy brain cell function. As such, the novel DOX@P1NS/TNC-FeLPs presented potent and precise anti-GBM capability and, therefore, are suggested here for the first time as a promising DDS to deliver therapeutic agents across the BBB for GBM treatment.

Pulmonary delivery of transferrin receptors targeting peptide surface-functionalized liposomes augments the chemotherapeutic effect of quercetin in lung cancer therapy

Purpose: Lung cancer has a high incidence rate worldwide with a 5-year survival rate of 18%, and is the leading cause of cancer-related deaths. The aim of this study is to augment therapeutic efficacy of quercetin (QR) for lung cancer therapy by targeting transferrin receptors, which are overexpressed and confined to tumor cells. Methods: In this study, T7 surface-functionalized liposomes loaded with QR (T7-QR-lip) having different T7 peptide densities (0.5%, 1% and 2%) were prepared by the film hydration method. T7 surface-functionalized liposomes were characterized and evaluated in terms of in vitro cytotoxicity and cellular uptake, 3D tumor spheroid penetration and inhibition capabilities, in vivo biodistribution and therapeutic efficacy in mice with orthotopic lung-tumor implantation by fluorescent and bioluminescent imaging via pulmonary administration. Results: In vitro, 2% T7-QR-lip exhibited significantly augmented cytotoxicity (~3-fold), higher apoptosis induction and S-phase cell-cycle arrest. A prominent peak right-shift and enhanced mean fluorescence intensity was observed in A549 cells treated with T7 Coumarin-6 liposomes (T7-Cou6-lip), confirming the target specificity of T7 targeted liposomes; while, after treatment with T7-QR-lip and non-targeted QR-lip, no significant difference was observed in cellular uptake and in vitro cytotoxicity studies in MRC-5 (normal lung fibroblast) cells. T7-Cou6-lip showed higher fluorescence intensity in A549 cells and a significantly deeper penetration depth of 120 µm in the core of the tumor spheroids and T7-QR-lip produced significantly higher tumor-spheroid growth inhibition. The in vivo biodistribution study via pulmonary delivery of T7 1,1'-dioctadecyltetramethyl-indotricarbocyanine iodide liposomes demonstrated liposome accumulation in the lungs and sustained-release behavior up to 96 h. Further, T7-QR-lip significantly enhanced the anticancer activity of QR and lifespan of mice (p<0.01, compared with saline) in orthotopic lung tumor-bearing mice via pulmonary administration. Conclusion: T7 surface-functionalized liposomes provide a potential drug delivery system for a range of anticancer drugs to enhance their therapeutic efficacy by localized (pulmonary) administration and targeted delivery.

Tumor Microenvironment Targeted Nanotherapy

Recent developments in nanotechnology have brought new approaches to cancer diagnosis and therapy. While enhanced permeability and retention effect promotes nano-chemotherapeutics extravasation, the abnormal tumor vasculature, high interstitial pressure and dense stroma structure limit homogeneous intratumoral distribution of nano-chemotherapeutics and compromise their imaging and therapeutic effect. Moreover, heterogeneous distribution of nano-chemotherapeutics in non-tumor-stroma cells damages the non-tumor cells, and interferes with tumor-stroma crosstalk. This can lead not only to inhibition of tumor progression, but can also paradoxically induce acquired resistance and facilitate tumor cell proliferation and metastasis. Overall, the tumor microenvironment plays a vital role in regulating nano-chemotherapeutics distribution and their biological effects. In this review, the barriers in tumor microenvironment, its consequential effects on nano-chemotherapeutics, considerations to improve nano-chemotherapeutics delivery and combinatory strategies to overcome acquired resistance induced by tumor microenvironment have been summarized. The various strategies viz., nanotechnology based approach as well as ligand-mediated, redox-responsive, and enzyme-mediated based combinatorial nanoapproaches have been discussed in this review.

Dual-ligand modified liposomes provide effective local targeted delivery of lung-cancer drug by antibody and tumor lineage-homing cell-penetrating peptide

The abilities of a drug delivery system to target and penetrate tumor masses are key factors in determining the system’s chemotherapeutic efficacy. Here, we explored the utility of an anti-carbonic anhydrase IX (anti-CA IX) antibody and CPP33 dual-ligand modified triptolide-loaded liposomes (dl-TPL-lip) to simultaneously enhance the tumor-specific targeting and increase tumor cell penetration of TPL. In vitro, the dl-TPL-lip increased the cytotoxicity of TPL in CA IX-positive lung cancer cells, which showed tunable size (137.6 ± 0.8 nm), high-encapsulation efficiency (86.3 ± 2.6%) and sustained release. Dl-TPL-lip significantly improved the ability of liposomes to penetrate 3 D tumor spheroids and exhibited a superior inhibiting effect. Furthermore, pharmacokinetic studies in rats that received TPL liposomal formulations by endotracheal administration showed a reduced concentration of TPL (17.3%–30.6% compared to free TPL) in systemic circulation. After pulmonary administration in orthotopic lung tumor-bearing mice, dl-TPL-lip significantly enhanced TPL anti-cancer efficacy without apparent systemic toxicity. This dual-ligand modified liposomal vehicle presents a potential system for localized and targeted delivery of anti-cancer drugs to improve their efficacy.

Overcoming Multidrug Resistance by Codelivery of MDR1-Targeting siRNA and Doxorubicin Using EphA10-Mediated pH-Sensitive Lipoplexes: In Vitro and In Vivo Evaluation

The therapeutic efficacy of chemotherapy is dramatically hindered by multidrug resistance (MDR), which is induced by the overexpression of P-glycoprotein (P-gp). The codelivery of an antitumor drug and siRNA is an effective strategy recently applied in overcoming P-gp-related MDR. In this study, a multifunctional drug delivery system with both pH-sensitive feature and active targetability was designed, in which MDR1-siRNA and DOX were successfully loaded. The resulting carrier EphA10 antibody-conjugated pH-sensitive doxorubicin (DOX), MDR1-siRNA coloading lipoplexes (shortened as DOX + siRNA/ePL) with high serum stability had favorable physicochemical properties. DOX + siRNA/ePL exhibited an incremental cellular uptake, enhanced P-gp downregulation efficacy, as well as a better cell cytotoxicity in human breast cancer cell line/adriamycin drug-resistant (MCF-7/ADR) cells. The results of the intracellular colocalization study indicated that DOX + siRNA/ePL possessed the ability for pH-responsive rapid endosomal escape in a time-dependent characteristic. Meanwhile, the in vivo antitumor activities suggested that DOX + siRNA/ePL could prolong the circulation time as well as specifically accumulate in the tumor cells via receptor-mediated endocytosis after intravenous administration into the blood system. The histological study further demonstrated that DOX + siRNA/ePL could inhibit the proliferation, induce apoptosis effect, and downregulate the P-gp expression in vivo. Altogether, DOX + siRNA/ePL was expected to be a suitable codelivery system for overcoming the MDR effect.

Tumor-targeting CuS nanoparticles for multimodal imaging and guided photothermal therapy of lymph node metastasis

Precise diagnosis of lymph node metastasis to guide lymphadenectomy is highly important for gastric cancer therapy in clinics. Though surgical dissection of regional metastatic lymph nodes remains the only way for gastric cancer therapy, the extended dissection may cause unavoidable postoperative risk of complications. It is still lack of effective method enabling the accurate removal of metastatic gastric cancer cells in lymph nodes with minimum injuries to normal tissue. Herein, we report a new fluorescent copper sulfide (CuS) nanoparticle (RGD-CuS-Cy5.5) enabling both non-invasive multimodality imaging and targeting photothermal therapy (PTT) of metastatic gastric cancer cells in lymph nodes. We demonstrate that RGD-CuS-Cy5.5 can easily drain into sentinel lymph nodes (SLN) after injection into primary tumors, and selectively enter into metastatic gastric MNK45 tumor cells via αvβ3 integrin-mediated endocytosis. The resulting strong near-infrared (NIR) fluorescence and computed tomography (CT) contrast in metastatic SLN compared to normal SLN can precisely differentiate SLN metastasis of gastric cancers. Guided by the imaging, localized PTT with RGD-CuS-Cy5.5 is conducted upon irradiation with an 808 nm laser, resulting in complete removal of metastatic gastric tumor cells in SLN without obvious toxicity. Moreover, RGD-CuS-Cy5.5 can also allow for the rapid and non-invasive self-monitoring of PTT efficacy against metastatic SLNs in living mice. This study highlights the potential of using RGD-CuS-Cy5.5 for imaging-guided and targeting PTT of SLN metastasis in vivo, which may be applicable for the metastatic gastric cancer therapy in clinics.

STATEMENT OF SIGNIFICANCE

RGD-CuS-Cy5.5 nanoparticles possess NIR fluorescence and CT signals for in vivo bimodality imaging of lymph node metastasis. Strong photothermal property under irradiation at 808 nm for efficient PTT. Easy drain into sentinel lymph nodes and selective enter metastatic gastric cancer cells via αvβ3 integrin-mediated endocytosis. Rapid and non-invasive monitoring of therapeutic efficacy against lymph node metastasis.

Radiofrequency hyperthermia promotes the therapeutic effects on chemotherapeutic-resistant breast cancer when combined with heat shock protein promoter-controlled HSV-TK gene therapy: Toward imaging-guided interventional gene therapy

Objective

Gene therapy is a frontier in modern medicine. In the present study, we explored a new technique for the effective treatment of multidrug-resistant (MDR) breast cancer by combining fully the advantages of multidisciplinary fields, including image-guided minimally invasive interventional oncology, radiofrequency technology, and direct intratumoral gene therapy.

Results

Combination treatment with P_HSP-TK plus RFH resulted in significantly higher TK gene transfection/expression, as well as a lower cell proliferation rate and a higher cell apoptosis index, than those of control groups. In vivo validation experiments with MRI confirmed that combination therapy resulted in a significant reduction of relative tumor volume compared with those of control animals, which was supported by the results of histologic and apoptosis analyses.

Materials and methods

The heat shock protein promoter (P_HSP) was used to precisely control the overexpression of thymidine kinase (TK) (P_HSP-TK). Serial in vitro experiments were performed to confirm whether radiofrequency hyperthermia (RFH) could enhance P_HSP-TK transfection and expression in a MDR breast cancer cell line (MCF7/Adr). Serial in vivo experiments were then carried out to validate the feasibility of the new technique, termed interventional RFH-enhanced direct intratumoral P_HSP-TK gene therapy. The therapeutic effect of combination therapy was evaluated by MRI and confirmed by subsequent laboratory correlation.

Conclusions

This study has established “proof-of-principle” of a new technique, interventional RFH-enhanced local gene therapy for MDR breast cancer, which may open new avenues for the effective management of MDR breast cancers via the simultaneous integration of interventional oncology, RF technology, and direct intratumoral gene therapy.

Surface Functionalization and Targeting Strategies of Liposomes in Solid Tumor Therapy: A Review

Surface functionalization of liposomes can play a key role in overcoming the current limitations of nanocarriers to treat solid tumors, i.e., biological barriers and physiological factors. The phospholipid vesicles (liposomes) containing anticancer agents produce fewer side effects than non-liposomal anticancer formulations, and can effectively target the solid tumors. This article reviews information about the strategies for targeting of liposomes to solid tumors along with the possible targets in cancer cells, i.e., extracellular and intracellular targets and targets in tumor microenvironment or vasculature. Targeting ligands for functionalization of liposomes with relevant surface engineering techniques have been described. Stimuli strategies for enhanced delivery of anticancer agents at requisite location using stimuli-responsive functionalized liposomes have been discussed. Recent approaches for enhanced delivery of anticancer agents at tumor site with relevant surface functionalization techniques have been reviewed. Finally, current challenges of functionalized liposomes and future perspective of smart functionalized liposomes have been discussed.

Anti-CD123 antibody-modified niosomes for targeted delivery of daunorubicin against acute myeloid leukemia

A novel niosomal delivery system was designed and investigated for the targeted delivery of daunorubicin (DNR) against acute myeloid leukemia (AML). Anti-CD123 antibodies conjugated to Mal-PEG₂₀₀₀-DSPE were incorporated into normal niosomes (NS) via a post insertion method to afford antibody-modified niosomes (CD123-NS). Next, NS was modified with varying densities of antibody (0.5 or 2%, antibody/Span 80, molar ratio), thus providing L-CD123-NS and H-CD123-NS. We studied the effect of antibody density on the uptake efficiency of niosomes in NB4 and THP-1 cells, on which CD123 express differently. Our results demonstrate CD123-NS showed significantly higher uptake efficiency than NS in AML cells, and the uptake efficiency of CD123-NS has been ligand density-dependent. Also, AML cells preincubated with anti-CD123 antibody showed significantly reduced cellular uptake of CD123-NS compared to control. Further study on the uptake mechanism confirmed a receptor-mediated endocytic process. Daunorubicin (DNR)-loaded H-CD123-NS demonstrated a 2.45- and 3.22-fold higher cytotoxicity, compared to DNR-loaded NS in NB4 and THP-1 cells, respectively. Prolonged survival time were observed in leukemic mice treated with DNR-H-CD123-NS. Collectively, these findings support that the CD123-NS represent a promising delivery system for the treatment of AML.

Light/magnetic hyperthermia triggered drug released from multi-functional thermo-sensitive magnetoliposomes for precise cancer synergetic theranostics

Precise delivery of antineoplastic drugs to specific tumor region has drawn much attention in recent years. Herein, a light/magnetic hyperthermia triggered drug delivery with multiple functionality is designed based on methotrexate (MTX) modified thermo-sensitive magnetoliposomes (MTX-MagTSLs). In this system, MTX and oleic acid modified magnetic nanoparticles (MNPs) can be applied in biological and magnetic targeting. Meanwhile, lipophilic fluorescent dye Cy5.5 and MNPs are encapsulated into the bilayer of liposomes, which can not only achieve dual-imaging effect to verify the MTX-MagTSLs accumulation in tumor region, but also provide an appropriate laser irradiation region to release Doxorubicin (Dox) under alternating magnetic field (AMF). Both in vitro and in vivo results revealed that MTX-MagTSLs possessed an excellent targeting ability towards HeLa cells and HeLa tumor-bearing mice. Furthermore, the heating effect of MTX-MagTSLs was amplified 4.2-fold upon combination with AMF and local precise near-infrared laser irradiation (808nm) (DUAL-mode) to rapidly reach the phase change temperature (Tm) of MTX-MagTSLs in 5min compared with either AMF or laser stimulation alone, resulting in a significantly enhanced release of Dox at tumor region and precise cancer synergetic theranostics.

Engineering thermosensitive liposome-nanoparticle hybrids loaded with doxorubicin for heat-triggered drug release

The engineering of responsive multifunctional delivery systems that combine therapeutic and diagnostic (theranostic) capabilities holds great promise and interest. We describe the design of thermosensitive liposome-nanoparticle (NP) hybrids that can modulate drug release in response to external heating stimulus. These hybrid systems were successfully engineered by the incorporation of gold, silver, and iron oxide NPs into the lipid bilayer of lysolipid-containing thermosensitive liposomes (LTSL). Structural characterization of LTSL-NP hybrids using cryo-EM and AFM revealed the incorporation of metallic NPs into the lipid membranes without compromising doxorubicin loading and retention capability. The presence of metallic NPs in the lipid bilayer reinforced bilayer retention and offered a nanoparticle concentration-dependent modulation of drug release in response to external heating. In conclusion, LTSL-NP hybrids represent a promising versatile platform based on LTSL liposomes that could further utilize the properties of the embedded NPs for multifunctional theranostic applications.

Focused Ultrasound-Triggered Release of Tyrosine Kinase Inhibitor From Thermosensitive Liposomes for Treatment of Renal Cell Carcinoma

This study reports, for the first time, development of tyrosine kinase inhibitor-loaded, thermosensitive liposomes (TKI/TSLs) and their efficacy for treatment of renal cell carcinoma when triggered by focused ultrasound (FUS). Uptake of these nanoparticles into renal cancer cells was visualized with confocal and fluorescent imaging of rhodamine B-loaded liposomes. The combination of TKI/TSLs and FUS was tested in an in vitro tumor model of renal cell carcinoma. According to MTT cytotoxic assay and flow cytometric analysis, the combined treatment led to the least viability (23.4% ± 2.49%, p < 0.001), significantly lower than that observed from treatment with FUS (97.6% ± 0.67%, not significant) or TKI/TSL (71.0% ± 3.65%, p < 0.001) at 96 h compared to control. The importance of this unique, synergistic combination was demonstrated in viability experiments with non-thermosensitive liposomes (TKI/NTSL + FUS: 58.8% ± 1.5% vs. TKI/TSL + FUS: 36.2% ± 1.4%, p < 0.001) and heated water immersion (TKI/TSL + WB43°: 59.3% ± 2.91% vs. TKI/TSL + FUS: 36.4% ± 1.55%, p < 0.001). Our findings coupled with the existing use of FUS in clinical practice make the proposed combination of targeted chemotherapy, nanotechnology, and FUS a promising platform for enhanced drug delivery and cancer treatment.

Ablative Focused Ultrasound Synergistically Enhances Thermally Triggered Chemotherapy for Prostate Cancer in Vitro

High-intensity focused ultrasound (HIFU) can locally ablate biological tissues such as tumors, i.e., induce their rapid heating and coagulative necrosis without causing damage to surrounding healthy structures. It is widely used in clinical practice for minimally invasive treatment of prostate cancer. Nonablative, low-power HIFU was established as a promising tool for triggering the release of chemotherapeutic drugs from temperature-sensitive liposomes (TSLs). In this study, we combine ablative HIFU and thermally triggered chemotherapy to address the lack of safe and effective treatment options for elderly patients with high-risk localized prostate cancer. DU145 prostate cancer cells were exposed to chemotherapy (free and liposomal Sorafenib) and ablative HIFU, alone or in combination. Prior to cell viability assessment by trypan blue exclusion and flow cytometry, the uptake of TSLs by DU145 cells was verified by confocal microscopy and cryogenic scanning electron microscopy (cryo-SEM). The combination of TSLs encapsulating 10 μM Sorafenib and 8.7W HIFU resulted in a viability of less than 10% at 72 h post-treatment, which was significant less than the viability of the cells treated with free Sorafenib (76%), Sorafenib-loaded TSLs (63%), or HIFU alone (44%). This synergy was not observed on cells treated with Sorafenib-loaded nontemperature sensitive liposomes and HIFU. According to cryo-SEM analysis, cells exposed to ablative HIFU exhibited significant mechanical disruption. Water bath immersion experiments also showed an important role of mechanical effects in the synergistic enhancement of TSL-mediated chemotherapy by ablative HIFU. This combination therapy can be an effective strategy for treatment of geriatric prostate cancer patients.

Characterization and in vitro evaluation of nimotuzumab conjugated with cisplatin-loaded liposomes

In this paper, we report the conjugation of the humanized monoclonal antibody nimotuzumab with cisplatin-loaded liposomes and the in vitro evaluation of its affinity for tumor cells. The conjugation procedure was performed through derivatization of nimotuzumab with N-succinimidyl S-acetylthioacetate (SATA) followed by a covalent attachment with maleimide groups at the end of PEG-DSPE chains located at the membrane of pre-formed liposomes. Confocal microscopy was performed to evaluate the immunoliposome affinity for EGFR antigens from human epidermoid carcinoma (A-431) and normal lung (MRC-5) cell lines. Results showed that the procedures implemented in this work do not affect the capability of the nimotuzumab-immunoliposomes to recognize the tumor cells, which overexpress the EGFR antigens.

Assessing Therapeutic Potential of Magnetic Mesoporous Nanoassemblies for Chemo-Resistant Tumors

Smart drug delivery system with strategic drug distribution is the future state-of-the-art treatment for any malignancy. To investigate therapeutic potential of such nanoparticle mediated delivery system, we examined the efficacy of dual drug-loaded, pH and thermo liable lipid coated mesoporous iron oxide-based magnetic nanoassemblies (DOX:TXL-LMMNA) in mice bearing both drug sensitive (A2780(S)) and drug resistant (A2780-CisR) ovarian cancer tumor xenografts. In presence of an external AC magnetic field (ACMF), DOX:TXL-LMMNA particles disintegrate to release encapsulated drug due to hyperthermic temperatures (41-45 ºC). In vivo bio distribution study utilizing the optical and magnetic properties of DOX:TXL-LMMNA particles demonstrated minimum organ specific toxicity. Noninvasive bioluminescence imaging of mice bearing A2780(S) tumors and administered with DOX-TXL-LMMNA followed by the application of ACMF revealed 65% less luminescence signal and 80% mice showed complete tumor regression within eight days. A six months follow-up study revealed absence of relapse in 70% of the mice. Interestingly, the A2780-CisR tumors which did not respond to drug alone (DOX:TXL) showed 80% reduction in luminescence and tumor volume with DOX:TXL-LMMNA after thermo-chemotherapy within eight days. Cytotoxic effect of DOX:TXL-LMMNA particles was more pronounced in A2780-CisR cells than in their sensitive counterpart. Thus these novel stimuli sensitive nanoassemblies hold great promise for therapy resistant malignancies and future clinical applications.

EGFR targeted thermosensitive liposomes: A novel multifunctional platform for simultaneous tumor targeted and stimulus responsive drug delivery

The epidermal growth factor receptor (EGFR) is a promising target for anti-cancer therapy. The aim of this study was to design thermosensitive liposomes (TSL), functionalized with anti-EGFR ligands for targeted delivery and localized triggered release of chemotherapy. For targeting, EGFR specific peptide (GE11) and Fab' fragments of cetuximab were used and the effect of ligand density on in vitro tumor targeting was investigated. Ligand conjugation did not significantly change the physicochemical characteristics of liposomes. Fab'-decorated TSL (Fab'-TSL) can specifically and more efficiently bind to the EGFR overexpressed cancer cells as compared to GE11 modified TSL. Calcein labeled Fab'-TSL showed adequate stability at 37°C in serum (<4% calcein released after 1h) and a temperature dependent release at above 40°C. FACS analysis and live cell imaging showed efficient and EGFR mediated cellular association as well as dramatic intracellular cargo release upon hyperthermia. Fab'-conjugation and hyperthermia induced enhanced tumor cell cytotoxicity of doxorubicin loaded TSL. The relative cytotoxicity of Fab'-TSL was also correlated to EGFR density on the tumor cells. These results suggest that Fab'-TSL showed great potential for combinational targeted and triggered release drug delivery.