Drug delivery to tumours: recent strategies

Evaluating the anticancer effects of carnosic acid against breast cancer: An In Vitro investigation

BACKGROUND

Carnosic acid (CA) has potential anti-cancer properties, but its effectiveness can be improved by combining it with Folic acid (FA). This research aimed to evaluate the impact of CA and CA-FA conjugate on breast cancer cell lines (MCF-7, MDA-MB-231, and MCA10).

MATERIALS AND METHODS

The viability of the cell lines was measured using the MTT assay, and the IC₅₀ was determined to compare the cytotoxicity of CA and CA-FA. The process of programmed cell death was investigated by utilizing Annexin V/PI staining, measuring caspase-3/7 activity, and real-time PCR for apoptotic gene expression. Reactive oxygen species (ROS) were also assessed to determine the extent of oxidative stress.

RESULTS

CA significantly decreased the viability of MCF-7 and MDA-MB-231 cells depending on the dosage, with CA-FA exhibiting enhanced cytotoxicity, particularly in MDA-MB-231 cells. The evaluation of IC₅₀ confirmed that conjugation with FA reduced the IC₅₀ of CA. Apoptosis analysis demonstrated increased apoptosis rates in MCF-7 and MDA-MB-231 cells exposed to treatment with CA and CA-FA, while MCA10 cells showed minimal effects. Caspase-3/7 activity was notably higher in CA-FA-treated cells. Gene expression analysis revealed elevated pro-apoptotic gene activity and reduced anti-apoptotic gene activity, with CA-FA having a more pronounced effect. Cells subjected to CA-FA treatment exhibited a significant increase in ROS levels.

CONCLUSION

These findings suggest that CA conjugation with FA enhances its cytotoxic effects and promotes apoptosis through increased apoptosis and ROS production. The research emphasizes the promise of CA-FA as a focused treatment approach for aggressive forms of breast cancer, underscoring the need for additional exploration of its practical uses in clinical settings.

Biotin functionalization of 8-hydroxyquinoline anticancer organometallics: low in vivo toxicity but potent in vitro activity

[M(arene)(HQ)Cl] complexes (M = RuII/OsII/RhIII/IrIII; HQ = 8-hydroxyquinoline) have shown promise as anticancer agents. To assess the effect of conjugating biotin (vitamin B7) to such compounds and improve their tumor-targeting ability through interaction with the sodium-dependent multivitamin transporter (SMVT), the chlorido co-ligand was exchanged with biotinylated 6-aminoindazole. The complexes were characterized by NMR spectroscopy and mass spectrometry, and purity was determined by elemental analysis. The compounds were shown to be stable in aqueous solution but reacted in particular with biologically relevant nitrogen-donor ligands. The biotinylated organometallics were shown to be able to interact with the high-affinity biotin-binding protein streptavidin using molecular modelling. High antiproliferative activity of the biotinylated Rh complex (IC50 = 1.1-10 μM) and its chlorido precursor (IC50 = 2.1-7.0 μM) was demonstrated in human HCT116, NCI-H460, COLO 205, SW620, A2780 and A2780cis cancer cells, which feature differing levels of SMVT expression. While there was no clear relationship between the anticancer activity in cells and SMVT expression, the complexes showed similar activity in cisplatin-sensitive and -resistant cells. The most potent was the biotinylated Rh derivative which displayed low toxicity toward zebrafish embryos with >75% survival up to day 4 and after treatment with up to 32 μM complex.

Encapsulation of HaCaT Secretome for Enhanced Wound Healing Capacity on Human Dermal Fibroblasts

In the epidermal and dermal layers of the skin, diverse cell types are reconstituted during the wound healing process. Delays or failures in wound healing are a major issue in skin therapy because they prevent the normal structure and function of wounded tissue from being restored, resulting in ulceration or other skin abnormalities. Human immortalized keratinocytes (HaCAT) cells are a spontaneously immortalized human keratinocyte cell line capable of secreting many bioactive chemicals (a secretome) that stimulate skin cell proliferation, rejuvenation, and regeneration. In this study, the HaCaT secretome was encapsulated with polyesters such as poly (lactic-co-glycolic acid) (PLGA) and cassava starch in an effort to maximize its potential. According to the estimated mechanism of the HaCaT secretome, all treatments were conducted on immortalized dermal fibroblast cell lines, a model of wound healing. Encapsulation of HaCaT secretome and cassava starch enhanced the effectiveness of cell proliferation, migration, and anti-aging. On the other hand, the levels of reactive oxygen species (ROS) were lowered, activating antioxidants in immortalized dermal fibroblast cells. The HaCaT secretome induced in a dose-dependent manner the expression of antioxidant-associated genes, including SOD, CAT, and GPX. Six cytokines, including CCL2 and MCP-1, influenced immunoregulatory and inflammatory processes in cultured HaCAT cells. HaCaT secretome encapsulated in cassava starch can reduce ROS buildup by boosting antioxidant to stimulate wound healing. Hence, the HaCaT secretome may have a new chance in the cosmetics business to develop components for wound prevention and healing.

Layer-by-Layer Polymer Functionalization Improves Nanoparticle Penetration and Glioblastoma Targeting in the Brain

Glioblastoma is characterized by diffuse infiltration into surrounding healthy brain tissues, which makes it challenging to treat. Complete surgical resection is often impossible, and systemically delivered drugs cannot achieve adequate tumor exposure to prevent local recurrence. Convection-enhanced delivery (CED) offers a method for administering therapeutics directly into brain tumor tissue, but its impact has been limited by rapid clearance and off-target cellular uptake. Nanoparticle (NP) encapsulation presents a promising strategy for extending the retention time of locally delivered therapies while specifically targeting glioblastoma cells. However, the brain's extracellular structure poses challenges for NP distribution due to its narrow, tortuous pores and a harsh ionic environment. In this study, we investigated the impact of NP surface chemistry using layer-by-layer (LbL) assembly to design drug carriers for broad spatial distribution in brain tissue and specific glioblastoma cell targeting. We found that poly-l-glutamate and hyaluronate were effective surface chemistries for targeting glioblastoma cells in vitro. Coadsorbing either polymer with a small fraction of PEGylated polyelectrolytes improved the colloidal stability without sacrificing cancer cell selectivity. Following CED in vivo, gadolinium-functionalized LbL NPs enabled MRI visualization and exhibited a distribution volume up to three times larger than liposomes and doubled the retention half-time up to 13.5 days. Flow cytometric analysis of CED-treated murine orthotopic brain tumors indicated greater cancer cell uptake and reduced healthy cell uptake for LbL NPs compared to nonfunctionalized liposomes. The distinct cellular outcomes for different colayered LbL NPs provide opportunities to tailor this modular delivery system for various therapeutic applications.

Functionalized lipid-based drug delivery nanosystems for the treatment of human infectious diseases

Infectious diseases are still public health problems. Microorganisms such as fungi, bacteria, viruses, and parasites are the main causing agents related to these diseases. In this context, the search for new effective strategies in prevention and/or treatment is considered essential, since current drugs often have side effects or end up, causing microbial resistance, making it a serious health problem. As an alternative to these limitations, nanotechnology has been widely used. The use of lipid-based drug delivery nanosystems (DDNs) has some advantages, such as biocompatibility, low toxicity, controlled release, the ability to carry both hydrophilic and lipophilic drugs, in addition to be easel scalable. Besides, as an improvement, studies involving the conjugation of signalling molecules on the surfaces of these nanocarriers can allow the target of certain tissues or cells. Thus, this review summarizes the performance of functionalized lipid-based DDNs for the treatment of infectious diseases caused by viruses, including SARS-CoV-2, bacteria, fungi, and parasites.

Polyprodrug Nanomedicines: An Emerging Paradigm for Cancer Therapy

Nanomedicines have the potential to provide advanced therapeutic strategies in combating tumors. Polymer-prodrug-based nanomedicines are particularly attractive in cancer therapies owing to the maximum drug loading, prolonged blood circulation, and reduced premature leakage and side effects in comparison with conventional nanomaterials. However, the difficulty in precisely tuning the composition and drug loading of polymer-drug conjugates leads to batch-to-batch variations of the prodrugs, thus significantly restricting their clinical translation. Polyprodrug nanomedicines inherit the numerous intrinsic advantages of polymer-drug conjugates and exhibit well-controlled composition and drug loading via direct polymerization of therapeutic monomers, representing a promising nanomedicine for clinical tumor therapies. In this review, recent advances in the development of polyprodrug nanomedicines are summarized for tumor elimination. Various types of polyprodrug nanomedicines and the corresponding properties are first summarized. The unique advantages of polyprodrug nanomedicines and their key roles in various tumor therapies are further highlighted. Finally, current challenges and the perspectives on future research of polyprodrug nanomedicines are discussed.

Nanoparticles use for Delivering Ursolic Acid in Cancer Therapy: A Scoping Review

Ursolic acid is a natural pentacyclic triterpenoid that exerts a potent anticancer effect. Furthermore, it is classified as a BCS class IV compound possessing low permeability and water solubility, consequently demonstrating limited bioavailability in addition to low therapeutic effectiveness. Nanoparticles are developed to modify the physical characteristics of drug and can often be produced in the range of 30-200 nm, providing highly effective cancer therapy due to the Enhanced Permeation and Retention (EPR) Effect. This study aims to provide a review of the efficacy and safety of various types of Ursolic Acid-loading nanoparticles within the setting of preclinical and clinical anticancer studies. This literature study used scoping review method, where the extracted data must comply with the journal inclusion criteria of within years of 2010-2020. The identification stage produced 237 suitable articles. Duplicate screening was then conducted followed by the initial selection of 18 articles that had been reviewed and extracted for data analysis. Based on this review, the use of nanoparticles can be seen to increase the anticancer efficacy of Ursolic Acid in terms of several parameters including pharmacokinetic data, survival rates and inhibition rates, as well as the absence of serious toxicity in preclinical and clinical trials in terms of several parameters including body weight, blood clinical chemistry, and organ histipathology. Based on this review, the use of nanoparticles has been able to increase the anticancer efficacy of Ursolic Acid, as well as show the absence of serious toxicity in preclinical and clinical trials. Evenmore, the liposome carrier provides development data that has reached the clinical trial phase I. The use of nanoparticle provides high potential for Ursolic Acid delivery in cancer therapy.

A novel dual-prodrug carried by cyclodextrin inclusion complex for the targeting treatment of colon cancer

BACKGROUND

There is an obvious correlation between ulcerative colitis and colorectal cancer, and the risk of colorectal cancer in patients with ulcerative colitis is increasing. Therefore, the combination therapy of anti-inflammatory and anti-tumor drugs may show promising to inhibit colon cancer. 5-aminosalicylic acid (5-ASA) with anti-inflammatory function is effective for maintaining remission in patients with ulcerative colitis and may also reduce colorectal cancer risk. Histone deacetylase (HDAC) plays an essential role in the progression of colon cancer. Butyric acid (BA) is a kind of HDAC inhibitor and thus shows tumor suppression to colon cancer. However, the volatile and corrosive nature of BA presents challenges in practical application. In addition, its clinical application is limited due to its non-targeting ability and low bioavailability. We aimed to synthesize a novel dual-prodrug of 5-ASA and BA, referred as BBA, to synergistically inhibit colon cancer. Further, based on the fact that folate receptor (FR) is over-expressed in most solid tumors and it has been identified to be a cancer stem cell surface marker in colon cancer, we took folate as the targeting ligand and used carboxymethyl-β-cyclodextrin (CM-β-CD) to carry BBA and thus prepared a novel inclusion complex of BBA/FA-PEG-CM-β-CD.

RESULTS

It was found that BBA/FA-PEG-CM-β-CD showed significant inhibition in cell proliferation against colon cancer cells SW620. It showed a pro-longed in vivo circulation and mainly accumulated in tumor tissue. More importantly, BBA/FA-PEG-CM-β-CD gave great tumor suppression effect against nude mice bearing SW620 xenografts.

CONCLUSIONS

Therefore, BBA/FA-PEG-CM-β-CD may have clinical potential in colon cancer therapy.

pH-Sensitive silica-based core–shell nanogel prepared via RAFT polymerization: investigation of the core size effect on the release profile of doxorubicin

The novelty of this work is the synthesis of a core–shell nanogel that is based on silica nanoparticles as the core with different sizes via RAFT polymerization and its application to drug delivery.

Nanoencapsulation of sophorolipids in PEGylated poly(lactide-co-glycolide) as a novel approach to target colon carcinoma in the murine model

Poly(lactic-co-glycolic acid) nanocapsules containing amphiphilic biosurfactant sophorolipids were formulated using a dispersion-based procedure. Di-block copolymers were used to vary peripheral poly(ethylene glycol) density, and variation in the oil core was used to achieve efficient encapsulation of the sophorolipid payload. Particulate size, zeta potential, encapsulation efficiency, release and stability were characterised. A glyceryl monocaprate core composition had the lowest particulate size, maximum encapsulation efficiency and optimum shelf-life stability compared to other formulations. This core composition was used to deliver sophorolipid to both in vitro and in vivo model tumour cell lines (CT26 murine colon carcinoma) and the effect of peripheral hydrophilicity was evaluated. Formulations with 10% poly(ethylene glycol) density achieved more than 80% reduction in cancer cell viability after 72 h and enhanced cellular uptake in CT26 cells. These formulations exhibited higher tumour accumulation and a longer blood circulation profile when compared to the non-poly(ethylene glycol)-containing nanocapsules. Animals treated with sophorolipid-loaded nanocapsules showed a tumour growth inhibition of 57% when compared to controls. An assessment of tumour mass within the same study cohort showed the biggest reduction when compared control and free drug-treated cohorts. This study shows that hydrophilic poly(lactic-co-glycolic acid) nanocapsules loaded with sophorolipids can address the poor intracellular delivery associated with these biosurfactants and is a promising approach for the treatment of colon neoplasia. Graphical abstract.

Natural products and phytochemical nanoformulations targeting mitochondria in oncotherapy: an updated review on resveratrol

Mitochondria are intracellular organelles with two distinct membranes, known as an outer mitochondrial membrane and inner cell membrane. Originally, mitochondria have been derived from bacteria. The main function of mitochondria is the production of ATP. However, this important organelle indirectly protects cells by consuming oxygen in the route of energy generation. It has been found that mitochondria are actively involved in the induction of the intrinsic pathways of apoptosis. So, there have been efforts to sustain mitochondrial homeostasis and inhibit its dysfunction. Notably, due to the potential role of mitochondria in the stimulation of apoptosis, this organelle is a promising target in cancer therapy. Resveratrol is a non-flavonoid polyphenol that exhibits significant pharmacological effects such as antioxidant, anti-diabetic, anti-inflammatory and anti-tumor. The anti-tumor activity of resveratrol may be a consequence of its effect on mitochondria. Multiple studies have investigated the relationship between resveratrol and mitochondria, and it has been demonstrated that resveratrol is able to significantly enhance the concentration of reactive oxygen species, leading to the mitochondrial dysfunction and consequently, apoptosis induction. A number of signaling pathways such as sirtuin and NF-κB may contribute to the mitochondrial-mediated apoptosis by resveratrol. Besides, resveratrol shifts cellular metabolism from glycolysis into mitochondrial respiration to induce cellular death in cancer cells. In the present review, we discuss the possible interactions between resveratrol and mitochondria, and its potential application in cancer therapy.

A Warburg effect targeting vector designed to increase the uptake of compounds by cancer cells demonstrates glucose and hypoxia dependent uptake

Glycoconjugation to target the Warburg effect provides the potential to enhance selective uptake of anticancer or imaging agents by cancer cells. A Warburg effect targeting group, rationally designed to facilitate uptake by glucose transporters and promote cellular accumulation due to phosphorylation by hexokinase (HK), has been synthesised. This targeting group, the C2 modified glucose analogue 2-(2-[2-(2-aminoethoxy)ethoxy]ethoxy)-D-glucose, has been conjugated to the fluorophore nitrobenzoxadiazole to evaluate its effect on uptake and accumulation in cancer cells. The targeting vector has demonstrated inhibition of glucose phosphorylation by HK, indicating its interaction with the enzyme and thereby confirming the potential to facilitate an intracellular trapping mechanism for compounds it is conjugated with. The cellular uptake of the fluorescent analogue is dependent on the glucose concentration and is so to a greater extent than is that of the widely used fluorescent glucose analogue, 2-NBDG. It also demonstrates selective uptake in the hypoxic regions of 3D spheroid tumour models whereas 2-NBDG is distributed primarily through the normoxic regions of the spheroid. The increased selectivity is consistent with the blocking of alternative uptake pathways.

Hollow S-nitrosothiols nanoparticle with polymeric brushes for nitric oxide (NO)-releasing as tumor targeted chemotherapy

A kind of tumor targeting nitric oxide donor nanoparticle with brushes is described in this paper. The poly(4-vinylphenylboronic acid) polymeric brush, which shows glucose and pH dual responsiveness, endows the ability of hollow S-nitrosothiols nanoparticle to accurate recognition and binding with the sialic acid over-expressed type tumor cells, such as HepG2 and MCF-7 cells. In vitro experiments, including cells capture and release experiments, confocal fluorescence microscope characterization, cytotoxicity assay with different cells, demonstrate the selective recognition and the controlled NO release to kill tumor cells for these S-nitrosothiols nanoparticles. Low concentration of the released NO from the S-nitrosothiols nanoparticles in the transmission would participate physiological activity and avoid serious side effects because the endogenous nature and the physiological necessity to regulate normal biological functions. To the best of our knowledge, this is the first report about polymer nanoparticles as NO donors with functional brushes to selectively identify tumor cells and release NO in a controlled manner.

SPIO labeling of endothelial cells using ultrasound and targeted microbubbles at diagnostic pressures

In vivo cell tracking of therapeutic, tumor, and endothelial cells is an emerging field and a promising technique for imaging cardiovascular disease and cancer development. Site-specific labeling of endothelial cells with the MRI contrast agent superparamagnetic iron oxide (SPIO) in the absence of toxic agents is challenging. Therefore, the aim of this in vitro study was to find optimal parameters for efficient and safe SPIO-labeling of endothelial cells using ultrasound-activated CD31-targeted microbubbles for future MRI tracking. Ultrasound at a frequency of 1 MHz (10,000 cycles, repetition rate of 20 Hz) was used for varying applied peak negative pressures (10–160 kPa, i.e. low mechanical index (MI) of 0.01–0.16), treatment durations (0–30 s), time of SPIO addition (-5 min– 15 min with respect to the start of the ultrasound), and incubation time after SPIO addition (5 min– 3 h). Iron specific Prussian Blue staining in combination with calcein-AM based cell viability assays were applied to define the most efficient and safe conditions for SPIO-labeling. Optimal SPIO labeling was observed when the ultrasound parameters were 40 kPa peak negative pressure (MI 0.04), applied for 30 s just before SPIO addition (0 min). Compared to the control, this resulted in an approximate 12 times increase of SPIO uptake in endothelial cells in vitro with 85% cell viability. Therefore, ultrasound-activated targeted ultrasound contrast agents show great potential for effective and safe labeling of endothelial cells with SPIO.

Structure-Guided Design and Synthesis of a Mitochondria-Targeting Near-Infrared Fluorophore with Multimodal Therapeutic Activities

An urgent challenge for imaging-guided disease-targeted multimodal therapy is to develop the appropriate multifunctional agents to meet the requirements for potential applications. Here, a rigid cyclohexenyl substitution in the middle of a polymethine linker and two asymmetrical amphipathic N-alkyl side chains to indocyanine green (ICG) (the only FDA-approved NIR contrast agent) are introduced, and a new analog, IR-DBI, is developed with simultaneous cancer-cell mitochondrial targeting, NIR imaging, and chemo-/PDT/PTT/multimodal therapeutic activities. The asymmetrical and amphipathic structural modification renders IR-DBI a close binding to albumin protein site II to form a drug-protein complex and primarily facilitates its preferential accumulation at tumor sites via the enhanced permeability and retention (EPR) effect. The released IR-DBI dye is further actively taken up by cancer cells through organic-anion-transporting polypeptide transporters, and the lipophilic cationic property leads to its selective accumulation in the mitochondria of cancer cells. Finally, based on the high albumin-binding affinity, IR-DBI is modified into human serum albumin (HSA) via self-assembly to produce a nanosized complex, which exhibits significant improvement in the cancer targeting and multimodal cancer treatment with better biocompatibility. This finding may present a practicable strategy to develop small-molecule-based cancer theranostic agents for simultaneous cancer diagnostics and therapeutics.

Tuning the Size of Poly(lactic-co-glycolic Acid) (PLGA) Nanoparticles Fabricated by Nanoprecipitation

Polymeric nanoparticles (PNPs) are promising drug carriers in cancer treatment. Size of the particles has a significant impact on drug loading, in vivo distribution, extravasation, intratumor diffusion and cell uptake, and thus is critical for the successful development of a drug delivery regime. However, methods for manufacturing PNPs of defined size are yet to be established. The goal of this study is to establish a method that can be used to fabricate PNPs with controlled size. The factors that could impact the size of PNPs fabricated by nano-precipitation are systematically investigated. The factors studied include polymer concentration, organic solvent, temperature, aqueous phase ionic strength, organic phase injection rate, aqueous phase agitation rate, gauge of the needles, and final polymer concentration. Polymer concentration, the choice of organic solvent, temperature, and the ionic strength of the aqueous phase are shown to have a significant impact on the size of PNPs, and the effect of these factors can be attributed to a single parameter, the diffusion coefficient of the solvent in water, D_pw . It is possible that by tightly control these four parameters, nanoparticles with highly predictable and desirable size with narrow size distribution can be fabricated.

On the chemotherapeutic agents localization in tissue by means of snake venoms

The efficiency of anti-tumour drug strongly depends on its dose. Higher drug doses and exposure times usually result in better treatment. It is why the implementation of high-dose treatment is always attractive. However, most of the drug delivery techniques meet essential limitations. In isolated regional perfusion a tumour can be exposed to high-dose therapeutic influence but the target organ may be isolated from the rest of circulatory system only for a relatively short period of time. During systemic injection of anti-tumour agents dose limitations are dictated by side toxicity danger. Viperidae venoms are known to cause local stagnation of blood flow and blood-tissue exchange processes in the place of snakebite. In present paper we suggest to use Viperidae snake venoms in addition to anti-tumour drugs for regional anti-cancer therapy. We suppose that Viperidae venoms will assist in drug localization. We state that their usage will help in high-dosage therapy implementation.

Selective synthesis of Fe3O4Au x Ag y nanomaterials and their potential applications in catalysis and nanomedicine

In these recent years, magnetite (Fe3O4) has witnessed a growing interest in the scientific community as a potential material in various fields of application namely in catalysis, biosensing, hyperthermia treatments, magnetic resonance imaging (MRI) contrast agents and drug delivery. Their unique properties such as metal-insulator phase transitions, superconductivity, low Curie temperature, and magnetoresistance make magnetite special and need further investigation. On the other hand, nanoparticles especially gold nanoparticles (Au NPs) exhibit striking features that are not observed in the bulk counterparts. For instance, the mentioned ferromagnetism in Au NPs coated with protective agents such as dodecane thiol, in addition to their aptitude to be used in near-infrared (NIR) light sensitivity and their high adsorptive ability in tumor cell, make them useful in nanomedicine application. Besides, silver nanoparticles (Ag NPs) are known as an antimicrobial agent. Put together, the [Formula: see text] nanocomposites with tunable size can therefore display important demanding properties for diverse applications. In this review, we try to examine the new trend of magnetite-based nanomaterial synthesis and their application in catalysis and nanomedicine.

Gadolinium-based layered double hydroxide and graphene oxide nano-carriers for magnetic resonance imaging and drug delivery

Gadolinium (Gd)-based contrasts remain one of the most accepted contrast agents for magnetic resonance imaging, which is among the world most recognized noninvasive techniques employed in clinical diagnosis of patients. At ionic state, Gd is considered toxic but less toxic in chelate form. A variety of nano-carriers, including gadolinium oxide (Gd₂O₃) nanoparticles have been used by researchers to improve the T1 and T2 contrasts of MR images. Even more recently, a few researchers have tried to incorporate contrast agents simultaneously with therapeutic agents using single nano-carrier for theranostic applications. The benefit of this concept is to deliver the drugs, such as anticancer drugs and at the same time to observe what happens to the cancerous cells. The delivery of both agents occurs concurrently. In addition, the toxicity of the anticancer drugs as well as the contrast agents will be significantly reduced due to the presence of the nano-carriers. The use of graphene oxide (GO) and layered double hydroxides (LDH) as candidates for this purpose is the subject of current research, due to their low toxicity and biocompatibility, which have the capacity to be used in theranostic researches. We review here, some of the key features of LDH and GO for simultaneous drugs and diagnostic agents delivery systems for use in theranostics applications.

Practical Issues with the Use of Stem Cells for Cancer Gene Therapy

Stem cell-based drug delivery for cancer therapy has steadily gained momentum in the past decade as several studies have reported stem cells' inherent tropism towards tumors. Since this science is still in its early stages and there are many factors that could significantly impact tumor tropism of stem cells, some contradictory results have been observed. This review starts by examining a number of proof-of-concept studies that demonstrate the potential application of stem cells in cancer therapy. Studies that illustrate stem cells' tumor tropism and discuss the technical difficulties that could impact the therapeutic outcome are also highlighted. The discussion also emphasizes stem cell imaging/tracking, as it plays a crucial role in performing reliable dose-response studies and evaluating the therapeutic outcome of treatment protocols. In each section, the pros and cons associated with each method are highlighted, limitations are underlined, and potential solutions are discussed. The overall intention is to familiarize the reader with important practical issues related to stem cell cancer tropism and in vivo tracking, underline the shortcomings, and emphasize critical factors that need to be considered for effective translation of this science into the clinic.

Self-Assembled Smart Nanocarriers for Targeted Drug Delivery

Nanostructured drug-carrier systems promise numerous benefits for drug delivery. They can be engineered to precisely control drug-release rates or to target specific sites within the body with a specific amount of therapeutic agent. However, to achieve the best therapeutic effects, the systems should be designed for carrying the optimum amount of a drug to the desired target where it should be released at the optimum rate for a specified time. Despite numerous attempts, fulfilling all of these requirements in a synergistic way remains a huge challenge. The trend in drug delivery is consequently directed toward integrated multifunctional carrier systems, providing selective recognition in combination with sustained or triggered release. Capsules as vesicular systems enable drugs to be confined for controlled release. Furthermore, carriers modified with recognition groups can enhance the capability of encapsulated drug efficacy. Here, recent advances are reviewed regarding designing and preparing assembled capsules with targeting ligands or size controllable for selective recognition in drug delivery.

Resveratrol loaded gelatin nanoparticles synergistically inhibits cell cycle progression and constitutive NF-kappaB activation, and induces apoptosis in non-small cell lung cancer cells

PURPOSE

Previously, we reported that the prepared resveratrol (RSV) loaded gelatin nanoparticles (GNPs) possessed enhanced anticancer effect than free RSV in non-small cell lung carcinoma cells and Swiss albino mice. The present study aims to explore the relevant mechanism of cell death induced by the combination of RSV-GNPs in NCI-H460 cells.

METHODS AND RESULTS

To increase its bioavailability and anticancer efficacy, we have encapsulated RSV-GNPs by Coacervation method. The detailed methods of preparation and characterization of RSV-GNPs were reported in our earlier publication. RSV-GNPs treated cells showed a further increased level of lipid peroxidative markers, i.e. TBARS and LHP in NCI-H460 cells. Activities of antioxidant enzymes SOD, CAT, GPx and GSH levels were decreased upon the treatment with RSV-GNPs in NCI-H460 cells. The nuclear fragmentation was evaluated by DAPI staining and data showed condensed apoptotic bodies upon treatment with the combination of RSV-GNPs compared to RSV alone treatment group. In addition, cell death induced by RSV-GNPs was mainly due to apoptosis which was characterized by a nuclear DNA fragmentation in a ladder-pattern was obtained from the genomic DNA analysis. Moreover, Western blotting analysis showed that apoptosis induced by RSV-GNPs is associated with the increased Bax, p53, p21, caspase-3 protein levels, and decreased Bcl-2 and NF-κB proteins expression, which indicates the involvement of mitochondria-dependent apoptosis in the anticancer efficacy of RSV-GNPs in NCI-H460 cells. It was also found that this enhanced anticancer efficacy of RSV-GNPs induced cell arrest in the G0/G1 phase of cell cycle.

CONCLUSIONS

Taken together, the results of our study clearly suggested that the cell death induced by the combination of RSV-GNPs would involve alteration in expression of p53, p21, caspase-3, Bax, Bcl-2 and NF-κB, indicating oxidative mechanism in NCI-H460 cells. Based on these results, it is concluded that GNPs is an ideal way to deliver RSV because of its high loading efficiency and superior efficacy in NCI-H460 cells.

Local, combination chemotherapy in prevention of cervical cancer recurrence after surgery by using nanofibers co-loaded with cisplatin and curcumin

Electrospun nanofibers co-loaded with cisplatin and curcumin effectively reduce the risk of local cervical cancer recurrence after surgery.

Investigation of cyanine dyes for in vivo optical imaging of altered mitochondrial membrane potential in tumors

Mitochondrial membrane potential (Δψm ) alteration is an important target for cancer diagnosis. In this study, we designed a series of near-infrared fluorescent cationic cyanine dyes with varying alkyl chain lengths (IC7-1 derivatives) to provide diverse lipophilicities and serum albumin-binding rates, and we evaluated the usefulness of these derivatives for in vivo Δψm imaging. IC7-1 derivatives with side chains from methyl to hexyl (IC7-1-Me to IC7-1-He) were synthesized, and their optical properties were measured. Cellular uptake and intracellular distribution were investigated with depolarized HeLa cells from carbonyl cyanine m-chlorophenylhydrazone (CCCP) treatment using a spectrofluorometer and a fluorescence microscope. Serum albumin-binding rates were evaluated using albumin-binding inhibitors. In vivo optical imaging was performed with HeLa cell xenograft mice following intravenous administration of IC7-1 derivatives with or without warfarin and CCCP as in vivo blocking agents. IC7-1 derivatives showing maximum excitation and emission wavelengths at 823 nm and ~845 nm, respectively, were synthesized. IC7-1-Me to -Bu showed fluorescence in mitochondria that decreased with CCCP treatment in a concentration-dependent manner, which showed that IC7-1-Me to -Bu successfully indicated Δψm . Tumors were clearly visualized after IC7-1-Bu administration. Treatment with warfarin or CCCP significantly decreased IC7-1-Bu fluorescence in the tumor region. In summary, IC7-1-Bu exhibited fluorescence localized to mitochondria dependent on Δψm , which enabled clear in vivo tumor imaging via serum albumin as a drug carrier for effective tumor targeting. Our data suggest that IC7-1-Bu is a promising NIR probe for in vivo imaging of the altered Δψm of tumor cells.

Ultrasound-assisted fabrication of a biocompatible magnetic hydroxyapatite

This work describes the fabrication and characterization of a biocompatible magnetic hydroxyapatite (HA) using an ultrasound-assisted co-precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) were used to characterize the structure and chemical composition of the produced samples. The M-H loops of synthesized materials were traced using a vibrating sample magnetometer (VSM) and the biocompatibility was evaluated by cell culture and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Furthermore, in vivo histopathological examinations were used to evaluate the potential toxicological effects of Fe₃O₄-HA composites on kidney of SD rats injected intraperitoneally with Fe₃O₄-HA particles. The results showed that magnetic iron oxide particles first replace OH ions of HA, which are parallel to the c axis, and then enter the HA crystal lattice which produces changes in the crystal surface of HA. Chemical bond interaction was observed between PO₄³⁻ groups of HA and iron ions of Fe₃O₄. The saturation magnetization (MS ) of Fe₃O₄-HA composites was 46.36 emu/g obtained from VSM data. Cell culture and MTT assays indicated that HA could affect the growth and proliferation of HEK-293 cells. This Fe₃O₄-HA composite produced no negative effects on cell morphology, viability, and proliferation and exhibited remarkable biocompatibility. Moreover, no inflammatory cell infiltration was observed in kidney histopathology slices. Therefore, this study succeeds to develop a Fe₃O₄-HA composite as a prospective biomagnetic material for future applications.

REVIEW OF METAL, CARBON AND POLYMER NANOPARTICLES FOR INFRARED PHOTOTHERMAL THERAPY

The aim of this review is to provide an up-to-date overview of nanoparticles developed for use as photothermal therapy agents (PTT) over the past five years. The main emphasis is on nanoparticles that absorb near infrared (NIR) light for PTT of cancer. Mild hyperthermia, including drug delivery, versus thermal ablation is also discussed. Recent advances in the synthesis of highly anisotropic novel metal nanoparticles for PTT are described. New metals and metal oxide complexes, as well as the use of quantum dots for PTT and as imaging agents are newer areas of development that are explained. This review also highlights current progress in the development of carbon nanoparticles, including reduced graphene oxide for both thermal ablation as well as drug delivery. The review culminates in the recent use electrically conductive polymer nanoparticles for hyperthermia. The advantages and unique features of these contemporary nanoparticles being used for PTT are highlighted. The goal of the present work is to describe the recent evolution of nanoparticles for NIR stimulated PTT, and highlight the innovations and future directions.

Assembly of bio-nanoparticles for double controlled drug release

A critical limiting factor of chemotherapy is the unacceptably high toxicity. The use of nanoparticle based drug carriers has significantly reduced the side effects and facilitated the delivery of drugs. Source of the remaining side effect includes (1) the broad final in vivo distribution of the administrated nanoparticles, and (2) strong basal drug release from nanoparticles before they could reach the tumor. Despite the advances in pH-triggered release, undesirable basal drug release has been a constant challenge under in vivo conditions. In this study, functionalized single walled carbon nanohorn supported immunoliposomes were assembled for paclitaxel delivery. The immunoliposomes were formulated with polyethylene glycol, thermal stable and pH sensitive phospholipids. Each nanohorn was found to be encapsulated within one immunoliposome. Results showed a highly pH dependent release of paclitaxel in the presence of serum at body temperature with minimal basal release under physiological conditions. Upon acidification, paclitaxel was released at a steady rate over 30 days with a cumulative release of 90% of the loaded drug. The drug release results proved our hypothesized double controlled release mechanism from the nanoparticles. Other results showed the nanoparticles have doubled loading capacity compared to that of traditional liposomes and higher affinity to breast cancer cells overexpressing Her2 receptors. Internalized nanoparticles were found in lysosomes.

Controlled block copolymer micelle formation for encapsulation of hydrophobic ingredients

We report on the formation of polymeric micelles in water using triblock copolymers with a polyethylene glycol middle block and various hydrophobic outer blocks prepared with the precipitation method. We form micelles in a reproducible manner with a narrow size distribution. This suggests that during the formation of the micelles the system had time to form micelles under close-to-thermodynamic control. This may explain why it is possible to use an equilibrium self-consistent field theory to predict the hydrodynamic size and the loading capacity of the micelles in accordance with experimental finding. Yet, the micelles are structurally quenched as concluded from the observation of size stability in time. We demonstrate that our approach enables to prepare rather hydrophobic block copolymer micelles with tunable size and loading.

Thermosensitive depot-forming injectable phosphatidylcholine blends tailored for localized drug delivery

A thermosensitive depot-forming system was developed for sustained and localized delivery of the anticancer drug, paclitaxel. The formulation is injectable as a melt slightly above the body temperature and forms a solid depot upon cooling to 37°C. The thermosensitive system was prepared by blending various combinations of phosphatidylcholines at specific weight ratios solubilized in laurinaldehyde. Of the blends investigated, distearoyl-phosphatidylcholine (DSPC) and egg-phosphatidylcholine (ePC) were found to be most miscible. A liquid-to-gel phase transition temperature (TC ) of 39°C was observed for the 70:30 (w/w) DSPC-ePC blend and a TC of 38.4°C with the addition of paclitaxel. Blends containing higher concentrations of ePC had a greater degree of swelling and weight loss. Furthermore, microscopy revealed an increase in porosity and erosion as the amount of ePC was increased in blends incubated in biologically relevant media. DSPC-ePC blends provided sustained release of paclitaxel over a 30-day period and the rate of drug release increased as the amount of ePC increased. Overall, the relationships established between the composition and properties of the blend may be employed to tailor the thermosensitive injectable formulation for localized chemotherapy of solid tumors.

Ultrasound-targeted microbubble destruction for chemotherapeutic drug delivery to solid tumors

Ultrasound-targeted microbubble destruction (UTMD) is a promising technique for non-invasive, targeted drug delivery, and its applications in chemotherapeutic drug delivery to solid tumors have attracted growing interest. Ultrasound, which has been conventionally used for diagnostic imaging, has evolved as a promising tool for therapeutic applications mainly because of its ability to be focused deep inside the human body, providing a modality for targeted delivery. Although originally being introduced into clinics as ultrasound contrast agents, microbubbles (MBs) have been developed as a diagnostic and therapeutic agent that can both be tracked through non-invasive imaging and deliver therapeutic agents selectively at ultrasound-targeted locations. Whereas free drugs often possess harmful side effects, their encapsulation in MBs and subsequent local release at the targeted tissue by ultrasound triggering may help improve the margin of safety. In the past 10 years, the feasibility and safety of UTMD have been extensively tested using normal animal models. Most recently, a growing number of preclinical studies have been reported on the therapeutic benefits of UTMD in the delivery of chemotherapeutic drugs to various malignant tumors, such as brain, liver, eyelid, pancreas, and breast tumors. Increased drug concentration in tumors and reduced tumor sizes were achieved in those tumors treated with UTMD in combination with chemotherapeutic drugs, when compared to tumors treated with chemotherapy drugs alone. This review presents an overview of current preclinical applications of UTMD in chemotherapeutic drug delivery for the treatment of cancers along with a discussion of its future developments.

Poly(acrylic acid) modified lanthanide-doped GdVO4 hollow spheres for up-conversion cell imaging, MRI and pH-dependent drug release

In this study, multifunctional poly(acrylic acid) modified lanthanide-doped GdVO(4) nanocomposites [PAA@GdVO(4): Ln(3+) (Ln = Yb/Er, Yb/Ho, Yb/Tm)] were constructed by filling PAA hydrogel into GdVO(4) hollow spheres via photoinduced polymerization. The up-conversion (UC) emission colors (green, red and blue) can be tuned by changing the codopant compositions in the matrices. The composites have potential applications as bio-probes for cell imaging. Meanwhile, the hybrid spheres can act as T(1) contrast agents for magnetic resonance imaging (MRI) owing to the existence of Gd(3+) ions on the surface of composites. Due to the nature of PAA, DOX-loaded PAA@GdVO(4):Yb(3+)/Er(3+) system exhibits pH-dependent drug releasing kinetics. A lower pH offers a faster drug release rate. Such character makes the loaded DOX easily released at cancer cells. The cell uptake process of drug-loaded composites was observed by using confocal laser scanning microscopy (CLSM). The results indicate the potential application of the multifunctional composites as theragnostics (effective bimodal imaging probes and pH-responsive drug carriers).

Poly(acrylic acid)-modified Fe3O4 microspheres for magnetic-targeted and pH-triggered anticancer drug delivery

Monodisperse poly(acrylic acid)-modified Fe(3)O(4) (PAA@Fe(3)O(4)) hybrid microspheres with dual responses (magnetic field and pH) were successfully fabricated. The PAA polymer was encapsulated into the inner cavity of Fe(3)O(4) hollow spheres by a vacuum-casting route and photo-initiated polymerization. TEM images show that the samples consist of monodisperse porous spheres with a diameter around 200 nm. The Fe(3)O(4) spheres, after modification with the PAA polymer, still possess enough space to hold guest molecules. We selected doxorubicin (DOX) as a model drug to investigate the drug loading and release behavior of as-prepared composites. The release of DOX molecules was strongly dependent on the pH value due to the unique property of PAA. The HeLa cell-uptake process of DOX-loaded PAA@Fe(3)O(4) was observed by confocal laser scanning microscopy (CLSM). After being incubated with HeLa cells under magnet magnetically guided conditions, the cytotoxtic effects of DOX-loaded PAA@Fe(3)O(4) increased. These results indicate that pH-responsive magnetic PAA@Fe(3)O(4) spheres have the potential to be used as anticancer drug carriers.

Cognitive effects of chemotherapy in breast cancer patients: a dose-response study

OBJECTIVE

The purpose of this study was to determine if cognition progressively worsens with cumulative chemotherapy exposure. We reasoned that the demonstration of such a 'dose-response' relationship would help to establish whether cognitive changes are caused by neurotoxic effects of chemotherapy or whether they are due to other confounding factors such as mood and pre-treatment differences in cognition.

METHODS

Sixty women with early stage breast cancer, aged 65 years or younger with no previous history of cancer or chemotherapy, were matched to 60 healthy women on age and education. Neuropsychological assessment was conducted after surgery but prior to commencing chemotherapy and then again following each chemotherapy cycle in patients and at yoked intervals in healthy controls. We used multilevel modeling to assess change over time in an overall cognitive summary score as well as domain-specific cognitive scores.

RESULTS

After controlling for baseline performance, age, education, and mood, the chemotherapy group showed a significant progressive decline over time relative to a matched healthy control group in an overall cognitive summary score, as well as in working memory, processing speed, verbal memory, and visual memory scores. A linear model best fit the trajectory of cognitive change over the course of treatment in the chemotherapy group supporting a dose-response hypothesis.

CONCLUSIONS

These results are in keeping with a dose-response relationship and provide the most compelling clinical evidence to date that cognitive decline is caused by chemotherapy exposure.

Improvement of drug safety by the use of lipid-based nanocarriers

Drug toxicity is an important factor that contributes significantly to adverse drug events in current healthcare practice. Application of lipid-based nanocarriers in drug formulation is one approach to improve drug safety. Lipid-based delivery systems include micelles, liposomes, solid lipid nanoparticles, nanoemulsions and nanosuspensions. These carriers are generally composed of physiological lipids well tolerated by human body. Delivery of water-insoluble drugs in these formulations increases their solubility and stability in aqueous media and eliminates the need for toxic co-solvents or pH adjustment to solubilize hydrophobic drugs. Association or encapsulation of peptides/proteins within lipid-based carriers protects the labile biologics against enzymatic degradation, hence reducing the therapeutic dose required and risk of dose-dependent toxicity. Most importantly, lipid-based nanocarriers alter the pharmacokinetics and biodistribution of drugs through passive and active targeting, leading to increased drug accumulation at target sites while significantly decreasing non-specific distribution to other tissues. Furthermore, surface modification of these nanocarriers reduces immunogenicity of drug-carrier complexes, imparts stealth by preventing opsonization and removal by phagocytes and minimizes interaction with circulating blood components. In view of heightening attention on drug safety in patient treatment, lipid-based nanocarrier is therefore an important and promising option for formulation of pharmaceutical products to improve treatment safety and efficacy.

Mucoadhesive fenretinide patches for site-specific chemoprevention of oral cancer: enhancement of oral mucosal permeation of fenretinide by coincorporation of propylene glycol and menthol

The objective of this study was to enhance oral mucosal permeation of fenretinide by coincorporation of propylene glycol (PG) and menthol in fenretinide/Eudragit RL PO mucoadhesive patches. Fenretinide is an extremely hydrophobic chemopreventive compound with poor tissue permeability. Coincorporation of 5-10 wt % PG (mean J(s) = 16-23 μg cm⁻² h⁻¹; 158-171 μg of fenretinide/g of tissue) or 1-10 wt % PG + 5 wt % menthol (mean J(s) = 18-40 μg cm⁻² h⁻¹; 172-241 μg of fenretinide/g of tissue) in fenretinide/Eudragit RL PO patches led to significant ex vivo fenretinide permeation enhancement (p < 0.001). Addition of PG above 2.5 wt % in the patch resulted in significant cellular swelling in the buccal mucosal tissues. These alterations were ameliorated by combining both enhancers and reducing PG level. After buccal administration of patches in rabbits, in vivo permeation of fenretinide across the oral mucosa was greater (∼43 μg fenretinide/g tissue) from patches that contained optimized permeation enhancer content (2.5 wt % PG + 5 wt % menthol) relative to permeation obtained from enhancer-free patch (∼17 μg fenretinide/g tissue) (p < 0.001). In vitro and in vivo release of fenretinide from patch was not significantly increased by coincorporation of permeation enhancers, indicating that mass transfer across the tissue, and not the patch, largely determined the permeation rate control in vivo. As a result of its improved permeation and its lack of deleterious local effects, the mucoadhesive fenretinide patch coincorporated with 2.5 wt % PG + 5 wt % menthol represents an important step in the further preclinical evaluation of oral site-specific chemoprevention strategies with fenretinide.

E-selectin liposomal and nanotube-targeted delivery of doxorubicin to circulating tumor cells

The presence of circulating tumor cells (CTCs) is believed to lead to the formation of secondary tumors via an adhesion cascade involving interaction between adhesion receptors of endothelial cells and ligands on CTCs. Many CTCs express sialylated carbohydrate ligands on their surfaces that adhere to selectin protein found on inflamed endothelial cells. We have investigated the feasibility of using immobilized selectin proteins as a targeting mechanism for CTCs under flow. Herein, targeted liposomal doxorubicin (L-DXR) was functionalized with recombinant human E-selectin (ES) and polyethylene glycol (PEG) to target and kill cancer cells under shear flow, both when immobilized along a microtube device or sheared in a cone-and-plate viscometer in a dilute suspension. Healthy circulating cells such as red blood cells were not targeted by this mechanism and were left to freely circulate, and minimal leukocyte death was observed. Halloysite nanotube (HNT)-coated microtube devices immobilized with nanoscale liposomes significantly enhanced the targeting, capture, and killing of cancer cells. This work demonstrates that E-selectin functionalized L-DXR, sheared in suspension or immobilized onto microtube devices, provides a novel approach to selectively target and deliver chemotherapeutics to CTCs in the bloodstream.