Amphiphilic chitosan-grafted-functionalized polylactic acid based nanoparticles as a delivery system for doxorubicin and temozolomide co-therapy

Establishment of an orthotopic glioblastoma mouse model for preclinical studies

Glioblastoma accounts almost 50% of all brain cancers, being the most common and lethal brain tumor in adults. Despite the current standard gold treatment based on surgery, chemotherapy, and radiotherapy, other treatment strategies are needed. Different in vitro models are currently used, including commercial cell lines, patient-derived cell lines, organoids, as well as in vivo models, being orthotopic xenografts the most used ones. In this chapter, we describe a standard protocol for the intracranial inoculation of glioblastoma cells in immunodeficient mice, and how to follow up the tumor progression and analyze the data.

Glioblastoma Therapy: Past, Present and Future

Glioblastoma (GB) stands out as the most prevalent and lethal form of brain cancer. Although great efforts have been made by clinicians and researchers, no significant improvement in survival has been achieved since the Stupp protocol became the standard of care (SOC) in 2005. Despite multimodality treatments, recurrence is almost universal with survival rates under 2 years after diagnosis. Here, we discuss the recent progress in our understanding of GB pathophysiology, in particular, the importance of glioma stem cells (GSCs), the tumor microenvironment conditions, and epigenetic mechanisms involved in GB growth, aggressiveness and recurrence. The discussion on therapeutic strategies first covers the SOC treatment and targeted therapies that have been shown to interfere with different signaling pathways (pRB/CDK4/RB1/P16ink4, TP53/MDM2/P14arf, PI3k/Akt-PTEN, RAS/RAF/MEK, PARP) involved in GB tumorigenesis, pathophysiology, and treatment resistance acquisition. Below, we analyze several immunotherapeutic approaches (i.e., checkpoint inhibitors, vaccines, CAR-modified NK or T cells, oncolytic virotherapy) that have been used in an attempt to enhance the immune response against GB, and thereby avoid recidivism or increase survival of GB patients. Finally, we present treatment attempts made using nanotherapies (nanometric structures having active anti-GB agents such as antibodies, chemotherapeutic/anti-angiogenic drugs or sensitizers, radionuclides, and molecules that target GB cellular receptors or open the blood-brain barrier) and non-ionizing energies (laser interstitial thermal therapy, high/low intensity focused ultrasounds, photodynamic/sonodynamic therapies and electroporation). The aim of this review is to discuss the advances and limitations of the current therapies and to present novel approaches that are under development or following clinical trials.

Intra-articular administration of PLGA resveratrol sustained-release nanoparticles attenuates the development of rat osteoarthritis

Our previous studies have confirmed that resveratrol (RSV) can prevent the development of osteoarthritis through a variety of mechanisms, such as apoptosis inhibition, autophagy induction and SIRT 1 activation. However, the pharmaceutical application of RSV is mainly limited by its low bioavailability. Here, we designed and synthesized RSV-loaded poly (D, l-lactide-coglycolide acid) (PLGA)-nanoparticles (NPs). The average particle size, polydispersity index and positive charge of RSV-loaded PLGA NPs were 50.40 nm, 0.217 and 12.57 mV, respectively. These nanoparticles had marked encapsulation efficiency (92.35 %) and drug loading (15.1 %) for RSV. It was found that RSV-loaded PLGA NPs not only inhibited the apoptosis of chondrocytes induced by IL-1, but also rescued GAG loss in vitro. Pharmacokinetic data showed that RSV-loaded PLGA NPs demonstrated a significantly profound and prolonged concentration profile in joint tissues, with quantifiable RSV concentrations over 35 days. The therapeutic effects of RSV-loaded PLGA NPs were then examined in rat osteoarthritis models. In vitro magnetic resonance imaging results showed that RSV-loaded PLGA NPs treatment dramatically reduced both T1ρ and T2 relaxation times at 4, 8, 12 weeks during administration, implying that cartilage destruction was alleviated. Histological assessments showed that RSV-loaded PLGA NPs significantly improved osteoarthritis symptoms. Gene expression analysis revealed that osteoarthritis mediator genes were downregulated in rats treated with RSV-PLGA NPs. Mechanistic studies indicated that RSV-loaded PLGA NPs inhibit apoptosis and promote autophagy. Collectively, this study demonstrates that intra-articular delivery of RSV via PLGA NPs might be an effective therapeutic approach for osteoarthritis.

A Review of Chitosan and Chitosan Nanofiber: Preparation, Characterization, and Its Potential Applications

Chitosan is produced by deacetylating the abundant natural chitin polymer. It has been employed in a variety of applications due to its unique solubility as well as its chemical and biological properties. In addition to being biodegradable and biocompatible, it also possesses a lot of reactive amino side groups that allow for chemical modification and the creation of a wide range of useful derivatives. The physical and chemical characteristics of chitosan, as well as how it is used in the food, environmental, and medical industries, have all been covered in a number of academic publications. Chitosan offers a wide range of possibilities in environmentally friendly textile processes because of its superior absorption and biological characteristics. Chitosan has the ability to give textile fibers and fabrics antibacterial, antiviral, anti-odor, and other biological functions. One of the most well-known and frequently used methods to create nanofibers is electrospinning. This technique is adaptable and effective for creating continuous nanofibers. In the field of biomaterials, new materials include nanofibers made of chitosan. Numerous medications, including antibiotics, chemotherapeutic agents, proteins, and analgesics for inflammatory pain, have been successfully loaded onto electro-spun nanofibers, according to recent investigations. Chitosan nanofibers have several exceptional qualities that make them ideal for use in important pharmaceutical applications, such as tissue engineering, drug delivery systems, wound dressing, and enzyme immobilization. The preparation of chitosan nanofibers, followed by a discussion of the biocompatibility and degradation of chitosan nanofibers, followed by a description of how to load the drug into the nanofibers, are the first issues highlighted by this review of chitosan nanofibers in drug delivery applications. The main uses of chitosan nanofibers in drug delivery systems will be discussed last.

Comparative study between two different morphological structures based on polylactic acid, nanocellulose and magnetite for co-delivery of flurouracil and curcumin

Cellulose was extracted from mango fibers and subjected to acid hydrolysis to obtain a nanofiber. Two morphological structures based on the polylactic acid (PLA)/nanocellulose (NC) combination have been synthesized and Fe₃O₄ NPs (M) are incorporated into both combinations. The first formulation is obtained by blending technique (PLA/M-NC) and the second formulation is obtained by self-assembly of grafted copolymer (M-PLA-co-NC). The magnetic nanocomposites are used as carriers for 5-fluorouracil (5-FU), an anti-cancer drug, and curcumin (CUR) to get PLA/M-NC/5-FU/CUR and M-PLA-co-NC/5-FU/CUR. The structural, morphological, and magnetic properties of the obtained nanocomposites were characterized by various techniques. The loading, release of 5-FU/CUR and the inhibition efficacy of nanocarriers loaded drugs against bacteria, HePG-2, MCF-7, and HCT-116 cell lines were studied. The two morphological forms of nanocarriers are considered close in loading % of 5-FU; however, the M-PLA-co-NC nanocarrier loaded double the loading % of CUR into PLA/M-NC nanocarrier, revealing superiority of copolymeric micelle than the blended formulation. The dual drugs loaded magnetic copolymeric micelles M-PLA-co-NC/5-FU/CUR revealed slower release, higher antibacterial and antitumor efficacy than the PLA/M-NC/5-FU/CUR. In this respect, the M-PLA-co-NC/5-FU/CUR could be considered a good nanomedicine against Streptococcus, Bacillus subtilis, Klebsiella pneumonia and Escherichia coli bacteria, besides the investigated cell lines.

Effect of Acyl Chain Length on Hydrophobized Cashew Gum Self-Assembling Nanoparticles: Colloidal Properties and Amphotericin B Delivery

Given its many potential applications, cashew gum hydrophobic derivatives have gained increasing attraction in recent years. We report here the effect of acyl chain length on hydrophobized cashew gum derivatives, using acetic, propionic, and butyric anhydrides on self-assembly nanoparticle properties and amphotericin B delivery. Nanoparticles with unimodal particle size distribution, highly negative zeta potential, and low PDI were produced. Butyrate cashew gum nanoparticles presented smaller size (<~100 nm) than acetylated and propionate cashew gum nanoparticles and no cytotoxicity in murine fibroblast cells was observed up to 100 µg/mL for loaded and unloaded nanoparticles. As a proof of concept of the potential use of the developed nanoparticle as a drug carrier formulation, amphotericin B (AmB) was encapsulated and fully characterized in their physicochemical, AmB association and release, stability, and biological aspects. They exhibited average hydrodynamic diameter lower than ~200 nm, high AmB efficiency encapsulations (up to 94.9%), and controlled release. A decrease in AmB release with the increasing of the anhydride chain length was observed, which explains the differences in antifungal activity against Candida albicans strains. An excellent storage colloidal stability was observed for unloaded and loaded AmB without use of surfactant. Considering the AmB delivery, the acyl derivative with low chain length is shown to be the best one, as it has high drug loading and AmB release, as well as low minimum inhibitory concentration against Candida albicans strains.

Application or function of citric acid in drug delivery platforms

Nontoxic materials with natural origin are promising materials in the designing and preparation of the new drug delivery systems (DDSs). Today's, citric acid (CA) has attracted a great deal of attention because of its special features; green nature, biocompatibility, low price, biodegradability, and commercially available property. So, CA has been employed in the preparation of the various platforms to induce a suitable property on their structure. Recently, several research groups investigated the CA-based platforms in different forms like tablets, dendrimers, hyperbranched polymers, (co)polymer, hydrogels, and nanoparticles as efficient DDSs. By considering an increasing amount of published articles in this field, for the first time, in this review, an overview of the published works regarding CA applications in the design of various DDSs is presented with a detailed and insightful discussion.

Biophysical properties of electrospun chitosan-grafted poly(lactic acid) nanofibrous scaffolds loaded with chondroitin sulfate and silver nanoparticles

The aim of this work was to study the biophysical properties of the chitosan-grafted poly(lactic acid) (CH-g-PLA) nanofibers loaded with silver nanoparticles (AgNPs) and chondroitin-4-sulfate (C₄S). The electrospun CH-g-PLA:AgNP:C₄S nanofibers were manufactured using the electrospinning technique. The microstructure of the CH-g-PLA:AgNP:C₄S nanofibers was investigated by proton nuclear magnetic resonance (¹H-NMR), scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), and Fourier transform infrared (ATR-FTIR) spectroscopy. ATR-FTIR and ¹H-NMR confirm the CH grafting successfully by PLA with a substitution degree of 33.4%. The SEM measurement results indicated apparently smooth nanofibers having a diameter range of 340 ± 18 nm with porosity of 89 ± 3.08% and an average pore area of 0.27 μm². UV-Vis and XRD suggest that silver nanoparticles with the size distribution of 30 nm were successfully incorporated into the electrospun nanofibers. The water contact angle of 12.8 ± 2.7° reveals the hydrophilic nature of the CH-g-PLA:AgNP:C₄S nanofibers has been improved by C₄S. The electrospun CH-g-PLA:AgNP:C₄S nanofibers are found to release ions Ag+ at a concentration level capable of rendering an antimicrobial efficacy. Gram-positive bacteria (S.aureus) were more sensitive to CH-g-PLA:AgNP:C₄S than Gram-negative bacteria (E. coli). The electrospun CH-g-PLA:AgNP:C₄S nanofibers exhibited no cytotoxicity to the L-929 fibroblast cells, suggesting cytocompatibility. Fluorescence microscopy demonstrated that C₄S promotes the adhesion and proliferation of fibroblast cells onto electrospun CH-g-PLA:AgNP:C₄S nanofibers.

Modular synthesis of amphiphilic chitosan derivatives based on copper-free click reaction for drug delivery

Amphiphilic chitosan derivatives have attracted wide attention as drug carriers due to their physicochemical properties. However, obtaining a desired amphiphilic chitosan derivative by tuning the various functional groups was complex and time-consuming. Therefore, a facile and common synthesis strategy would be promising. In this study, a modular strategy based on strain-promoted azide-alkyne cycloaddition (SPAAC) click reaction was designed and applied in synthesizing deoxycholic acid- or octanoic acid-modified N-azido propionyl-N,O-sulfate chitosan through tuning the hydrophobic groups. Additionally, chitosan derivatives with the same substitute groups were prepared via amide coupling as controls. We demonstrated that these derivates via the two strategies showed no obvious difference in physicochemical properties, drug loading ability and biosafety, indicating the feasibility of modular strategy. Notably, the modular strategy exhibited advantages including high reactivity, flexibility and reproducibility. We believe that this modular strategy could provide varied chitosan derivatives in an easy and high-efficiency way for improving multifunctional drug carriers.

Multiresponsive Hybrid Microparticles for Stimuli-Responsive Delivery of Bioactive Compounds

Hybrid microparticles based on an iron core and an amphiphilic polymeric shell have been prepared to respond simultaneously to magnetic and ultrasonic fields and variation in the surrounding pH to trigger and modulate the delivery of doxorubicin. The microparticles have been developed in four steps: (i) synthesis of the iron core; (ii) surface modification of the core; (iii) conjugation with the amphiphilic poly(lactic acid)-grafted chitosan; and (iv) doxorubicin loading. The particles demonstrate spherical shape, a size in the range of 1–3 µm and surface charge that is tuneable by changing the pH of the environment. The microparticles demonstrate good stability in simulated physiological solutions and are able to hold up to 400 µg of doxorubicin per mg of dried particles. The response to ultrasound and the changes in the shell structure during exposure to different pH levels allows the control of the burst intensity and release rate of the payload. Additionally, the magnetic response of the iron core is preserved despite the polymer coat. In vitro cytotoxicity tests performed on fibroblast NIH/3T3 demonstrate a reduction in the cell viability after administration of doxorubicin-loaded microparticles compared to the administration of free doxorubicin. The application of ultrasound causes a burst in the release of the doxorubicin from the carrier, causing a decrease in cell viability. The microparticles demonstrate in vitro cytocompatibility and hemocompatibility at concentrations of up to 50 and 60 µg/mL, respectively.

Self-assembling cashew gum-graft-polylactide copolymer nanoparticles as a potential amphotericin B delivery matrix

Amphotericin B is an antibiotic used in the treatment of fungal disease and leishmania; however, it exhibits side effects to patients, hindering its wider application. Therefore, nanocarriers have been investigated as delivery systems for amphotericin B (AMB) in order to decrease its toxicity, besides increase bioavailability and solubility. Amphiphilic copolymers are interesting materials to encapsulate hydrophobic drugs such as AMB, hence copolymers of cashew gum (CG) and l-lactide (LA) were synthesized using two different CG:LA molar ratios (1:1 and 1:10). Data obtained revealed that copolymer nanoparticles present similar figures for particle sizes and zeta potentials; however, particle size of encapsulated AMB increases if compared to unloaded nanoparticles. The 1:10 nanoparticle sample has better stability although higher polydispersity index (PDI) if compared to 1:1 sample. High amphotericin (AMB) encapsulation efficiencies and low hemolysis were obtained. AMB loaded copolymers show lower aggregation pattern than commercial AMB solution. AMB loaded nanoparticles show antifungal activities against four C. albicans strains. It can be inferred that cashew gum/polylactide copolymers have potential as nanocarrier systems for AMB.

Etoricoxib-loaded bio-adhesive hybridized polylactic acid-based nanoparticles as an intra-articular injection for the treatment of osteoarthritis

Osteoarthritis is a major problem in elder people. Etoricoxib-loaded bio-adhesive hybridized nanoparticles were prepared using polylactic acid (PLA) and chitosan hydrochloride (CS-HCl) in presence of Captex®200 as a liquid oil, polyvinyl alcohol (PVA) and Tween®80 as surfactants. The study aimed to present a new intra-articular treatment of osteoarthritis with anti-inflammatory as well as bone rebuilding effects. Hybridized nanoparticles were fabricated applying the emulsion solvent evaporation technique then assessed for particle size, zeta potential, entrapment efficiency and in-vitro drug release. Furthermore, FT-IR and DSC in addition to morphological examination were done. Results revealed that the formulation composed of PLA:Captex®200 in ratio 1:2 (w/w), 1%w/v Tween®80, 0.3% w/v CS-HCl and 3%w/v PVA possessed the smallest particle size and the most sustained drug release, thus was sorted for further analyses. The selected formulation ability to interact with the negatively charged sodium fluroscein was evaluated to predict its binding with the naturally occurring hyaluronic acid in the knee joint where promising results were obtained. Results showed the cytocompatibility of the formulation when tested using MC3T3-E1 normal bone cell line, enhanced ALP activity and increased calcium ion deposition and binding. Results suggested that the presented formulation can be considered as an innovative approach for osteoarthritis.

Biodegradable Chitosan-graft-Poly(l-lactide) Copolymers For Bone Tissue Engineering

The design and synthesis of new biomaterials with adjustable physicochemical and biological properties for tissue engineering applications have attracted great interest. In this work, chitosan-graft-poly(l-lactide) (CS-g-PLLA) copolymers were prepared by chemically binding poly(l-lactide) (PLLA) chains along chitosan (CS) via the "grafting to" approach to obtain hybrid biomaterials that present enhanced mechanical stability, due to the presence of PLLA, and high bioactivity, conferred by CS. Two graft copolymers were prepared, CS-g-PLLA(80/20) and CS-g-PLLA(50/50), containing 82 wt % and 55 wt % CS, respectively. Degradation studies of compressed discs of the copolymers showed that the degradation rate increased with the CS content of the copolymer. Nanomechanical studies in the dry state indicated that the copolymer with the higher CS content had larger Young modulus, reduced modulus and hardness values, whereas the moduli and hardness decreased rapidly following immersion of the copolymer discs in alpha-MEM cell culture medium for 24 h. Finally, the bioactivity of the hybrid copolymers was evaluated in the adhesion and growth of MC3T3-E1 pre-osteoblastic cells. In vitro studies showed that MC3T3-E1 cells exhibited strong adhesion on both CS-g-PLLA graft copolymer films from the first day in cell culture, whereas the copolymer with the higher PLLA content, CS-g-PLLA(50/50), supported higher cell growth.

Biocompatibility Profile and In Vitro Cellular Uptake of Self-assembled Alginate Nanoparticles

Polymeric nanoparticles could offer promising controlled drug delivery. The biocompatibility is of extreme importance for future applications in humans. Self-assembled polymeric nanoparticles based on phenylalanine ethyl ester (PAE)-modified alginate (Alg) had been successfully prepared and characterized in our lab. However, little is known about their interaction with cells and other biological systems. In this study, nanoparticles (NPs) based on PAE-Alg conjugates (PEA-NPs) with different degree of substitution (DS) were prepared and investigated. Our results showed that PEA-NPs had no effects on the proliferation of the human intestinal epithelial Caco-2 cells at concentrations up to 1000 μg/mL. Furthermore, the in vitro cellular uptake profile of PEA-NPs, concerning several parameters involved in the application of therapeutic or diagnostic NPs, such as NPs concentration, time and temperature, was described. Different NPs have been adopted for cellular uptake studies and the NPs internalized into Caco-2 cells were quantified. Cellular uptake efficiency could reach 60% within 4 h. PEA-NPs also showed greater cell permeability than oleoyl alginate ester nanoparticles (OAE-NPs) previously prepared in our lab. Our studies reveal that NPs based on PEA conjugate are promising nanosystems for cellular delivery.

N-(2-Hydroxy)-propyl-3-trimethylammonium, O-Mysristoyl Chitosan Enhances the Solubility and Intestinal Permeability of Anticancer Curcumin

An amphiphilic derivative of chitosan containing quaternary ammonium and myristoyl groups, herein named as ammonium myristoyl chitosan (DMCat), was synthesized by reacting glycidyltrimethylammonium chloride (GTMAC) and myristoyl chitosan (DMCh). The success of the modification was confirmed using Fourier-transform infrared spectroscopy (FTIR) and ¹H nuclear magnetic resonance (NMR) spectroscopy. The average degrees of alkylation and quaternization (DQ¯) were determined by using ¹H NMR and conductometric titration. The zeta potential of the micelles was higher than 28 mV while its average size and encapsulation efficiency ranged from 280 nm to 375 nm and 68% to 100%, respectively. The in vitro cytotoxicity of the unloaded and curcumin (CUR)-loaded micelles was tested against Caco-2 and HT29-MTX intestinal epithelial cell lines. The results showed no cytotoxic effect from loaded and unloaded micelles as compared to free CUR. In the permeability test, it was observed that both types of micelles, i.e., DMCh and DMCat, improved CUR permeability. Additionally, higher permeability was verified for both systems in Caco-2/HT29-MTX:Raji B because of the mucoadhesive character of chitosan and its ability to open tight junctions. The results indicated that DMCat micelles, due to the physico-chemical, improved characteristics may be a promising carrier to encapsulate CUR aiming cancer therapy.

Hyperbaric oxygen as an adjuvant to temozolomide nanoparticle inhibits glioma growth by inducing G2/M phase arrest

AIM

To study the effects of combinational treatment of hyperbaric oxygen (HBO) and nanotemozolomide in glioma.

MATERIALS & METHODS

Temozolomide (TMZ)-loaded porous silicon nanoparticles (TMZ/PSi NPs) were prepared. In vitro and in vivo evaluations were performed.

RESULTS

The cell uptake of TMZ/PSi NPs could be tracked by autofluorescence of porous silicon. The concentration of oxygen in tumor was improved and the antitumor rate was increased to 84.2% in the TMZ/PSi NPs combined with HBO group. The viability of hypoxia-induced glioma C6 cells was decreased and cell cycle was arrested at G2/M phase in response to TMZ/PSi NPs treatment with HBO compared with continuous treatment with hypoxia.

CONCLUSION

The combinational treatment of TMZ/PSi NPs and HBO could be a promising therapeutic strategy for glioma.

Zinc-Modified Nanotransporter of Doxorubicin for Targeted Prostate Cancer Delivery

This work investigated the preparation of chitosan nanoparticles used as carriers for doxorubicin for targeted cancer delivery. Prepared nanocarriers were stabilized and functionalized via zinc ions incorporated into the chitosan nanoparticle backbone. We took the advantage of high expression of sarcosine in the prostate cancer cells. The prostate cancer targeting was mediated by the AntiSar antibodies decorated surface of the nanocage. Formation of the chitosan nanoparticles was determined using a ninhydrin assay and differential pulse voltammetry. Obtained results showed the strong effect of tripolyphosphine on the nanoparticle formation. The zinc ions affected strong chitosan backbone coiling both in inner and outer chitosan nanoparticle structure. Zinc electrochemical signal depended on the level of the complex formation and the potential shift from -960 to -950 mV. Formed complex is suitable for doxorubicin delivery. It was observed the 20% entrapment efficiency of doxorubicin and strong dependence of drug release after 120 min in the blood environment. The functionality of the designed nanotransporter was proven. The purposed determination showed linear dependence in the concentration range of Anti-sarcosine IgG labeled gold nanoparticles from 0 to 1000 µg/mL and the regression equation was found to be y = 3.8x - 66.7 and R² = 0.99. Performed ELISA confirmed the ability of Anti-sarcosine IgG labeled chitosan nanoparticles with loaded doxorubicin to bind to the sarcosine molecule. Observed hemolytic activity of the nanotransporter was 40%. Inhibition activity of our proposed nanotransporter was evaluated to be 0% on the experimental model of S. cerevisiae. Anti-sarcosine IgG labeled chitosan nanoparticles, with loaded doxorubicin stabilized by Zn ions, are a perspective type of nanocarrier for targeted drug therapy managed by specific interaction with sarcosine and metallothionein for prostate cancer.

Enhancement of temozolomide stability by loading in chitosan-carboxylated polylactide-based nanoparticles

In the presented work, amphiphilic nanoparticles based on chitosan and carboxy-enriched polylactic acid have been prepared to improve the stability of the pro-drug temozolomide in physiological media by encapsulation. The carrier, with a diameter in the range of 150-180 nm, was able to accommodate up to 800 μg of temozolomide per mg of polymer. The obtained formulation showed good stability in physiological condition and preparation media up to 1 month. Temozolomide loaded inside the carrier exhibited greater stability than the free drug, in particular in simulated physiological solution at pH 7.4 where the hydrolysis in the inactive metabolite was clearly delayed. CS-SPLA nanoparticles demonstrated a pH-dependent TMZ release kinetics with the opportunity to increase or decrease the rate. Mass spectroscopy, UV-Vis analysis, and in vitro cell tests confirmed the improvement in temozolomide stability and effectiveness when loaded into the polymeric carrier, in comparison with the free drug.

Noncovalent interaction assisted fullerene for the transportation of some brain anticancer drugs: A theoretical study

The treatment of brain cancer like glioblastoma multiforme often uses chemotherapeutic drugs like temozolomide, procarbazine, carmustine, and lomustine. Fullerene loaded with these drugs help to cross the blood brain barriers. The adsorptions of the four drug molecules on the surface of the fullerene are studied mostly by using density functional theory (DFT) based method at the M06-2X/6-31G(d) level of calculations. In all four cases, the estimated interactions are noncovalent type and the average adsorption energy lies in between -5 and -11kcal/mol in the gas phase. In the aqueous and protein environment such interactions are weakened further. The binding affinity is further assessed by performing MP2 based calculations to provide interaction energies with a reasonable accuracy. Stabilities and reactivities of the drug adsorbed fullerene complexes are determined from chemical reactivity descriptors. The attached drug molecules increase the polarity of the pristine C₆₀ thus facilitating the drug delivery within the biological systems. The semiconducting behavior of C₆₀ is retained in the C₆₀-drug composite systems. The computed DOS, IR, UV spectra, and molecular orbitals in the vicinity of Fermi level are analyzed to reveal the nature of the noncovalent interactions between C₆₀ and drug molecules. The Wiberg bond order values are used to estimate the strength of the adsorption of the drug molecule on C₆₀. In all four C₆₀-drug interactions, the chemical characteristics of the drug molecule are least perturbed by the C₆₀ moiety thereby suggesting it to be a good carrier for the delivery of these brain anticancer drug molecules to the target cells.

Branched polyesters: Preparative strategies and applications

In the last 20years, the availability of precision chemical tools (e.g. controlled/living polymerizations, 'click' reactions) has determined a step change in the complexity of both the macromolecular architecture and the chemical functionality of biodegradable polyesters. A major part in this evolution has been played by the possibilities that controlled macromolecular branching offers in terms of tailored physical/biological performance. This review paper aims to provide an updated overview of preparative techniques that derive hyperbranched, dendritic, comb, grafted polyesters through polycondensation or ring-opening polymerization mechanisms.

Nano-structures mediated co-delivery of therapeutic agents for glioblastoma treatment: A review

Glioblastoma is a malignant brain tumor and leads to death in most patients. Chemotherapy is a common method for brain cancer in clinics. However, the recent advancements in the chemotherapy of brain tumors have not been efficient enough. With the advancement of nanotechnology, the used drugs can enhance chemotherapy efficiency and increase the access to brain cancers. Combination of therapeutic agents has been recently attracted great attention for glioblastoma chemotherapy. One of the early benefits of combination therapies is the high potential to provide synergistic effects and decrease adverse side effects associated with high doses of single anticancer drugs. Therefore, brain tumor treatments with combination drugs can be considered as a crucial approach for avoiding tumor growth. This review investigates current progress in nano-mediated co-delivery of therapeutic agents with focus on glioblastoma chemotherapy prognosis.

Acidic pH-targeted chitosan capped mesoporous silica coated gold nanorods facilitate detection of pancreatic tumors via multispectral optoacoustic tomography

We present a cancer nanomedicine based on acidic pH targeted gold nanorods designed for multispectral optoacoustic tomography (MSOT). We have designed gold nanorods coated with mesoporous silica and subsequently capped with chitosan (CMGs). We have conjugated pH-sensitive variant 7 pHLIP peptide to the CMGs (V7-CMG) to provide targeting specificity to the acidic tumor microenvironment. In vitro, treatment of S2VP10 and MiaPaca2 cells with V7-CMG containing gemcitabine resulted in significantly greater cytotoxicity with 97% and 96.5% cell death, respectively than gemcitabine alone 60% and 76% death at pH 6.5 (S2VP10 pH 6.5 p=0.009; MiaPaca2 pH 6.5 p=0.0197). In vivo, the V7-CMGs provided the contrast and targeting specificity necessary for MSOT of retroperitoneal orthotopic pancreatic tumors. In the in vivo S2VP10 model, the V7-CMG particle preferentially accumulated within the tumor at 17.1 MSOT a.u. signal compared with 0.7 MSOT a.u. in untargeted CMG control in tumor (P = 0.0002). Similarly, V7-CMG signal was 9.34 MSOT a.u. in the S2013 model compared with untargeted CMG signal at 0.15 MSOT a.u. (P = 0.0004). The pH-sensitivity of the targeting pHLIP peptide and chitosan coating makes the particles suitable for simultaneous in vivo tumor imaging and drug delivery.

Cyclodextrin-based nanosponges: a versatile platform for cancer nanotherapeutics development

Nanosponges (NSs) are a new age branched cyclodextrin (CD) polymeric systems exhibiting tremendous potential in pharmaceutical, agro science, and biomedical applications. Over the past decade, different varieties of NS based on the type of CD and the crosslinker have been developed tailored for specific applications. NS technology has been instrumental in achieving solubilization, stabilization, sustained release, enhancement of activity, permeability enhancement, protein delivery, ocular delivery, stimuli sensitive drug release, enhancement of bioavailability, etc. There is a major explosion of research in the area of NS-aided cancer therapeutics. A wide of anticancer molecules both from a pharmacological and physicochemical perspective have been developed as NS formulations by several groups including ours. Our objective in this review is to capture a systematic and comprehensive snapshot of the state-of-the-art of NS-aided cancer therapeutics reported so far. This review will provide an ideal platform for both the formulation scientists working on new polymeric/drug development and cancer biologists/scientists to understand the current nanotechnologies in CD-based NS-aided cancer therapeutics. The scope of the review is limited to small molecules and CD-based NS. The review covers in detail the problems associated with anticancer small molecules, and the solution provided by CD-based NS specifically for camptothecin, curcumin, paclitaxel, tamoxifen, resveratrol, quercetin, oxygen-NS, temozolomide, doxorubicin, and 5-Fluorouracil. WIREs Nanomed Nanobiotechnol 2016, 8:579-601. doi: 10.1002/wnan.1384 For further resources related to this article, please visit the WIREs website.

Polymeric nanoparticles based on chitooligosaccharide as drug carriers for co-delivery of all-trans-retinoic acid and paclitaxel

An amphiphilic all-trans-retinoic acid (ATRA)-chitooligosaccharide (RCOS) conjugate was synthesized to form self-assembled polymeric nanoparticles to facilitate the co-delivery of ATRA and paclitaxel (PTX). The blank RCOS nanoparticles possessed low hemolytic activity and cytotoxicity, and could efficiently load PTX with a drug loading of 22.2% and a high encapsulation efficiency of 71.3%. PTX-loaded RCOS nanoparticles displayed a higher cytotoxicity to HepG2 cells compared to PTX plus ATRA solution when corrected by the accumulated drug release. Cellular uptake profiles of RCOS nanoparticles were evaluated via confocal laser scanning microscope and flow cytometry with FITC as a fluorescent mark. The RCOS nanoparticles could be rapidly and continuously taken up by HepG2 cells via endocytosis and transported into the nucleus, and the uptake rates increased with particle concentration. These results revealed the promising potential of RCOS nanoparticles as drug carriers for co-delivery of ATRA and PTX or other hydrophobic therapeutic agents.

A facile strategy to generate polymeric nanoparticles for synergistic chemo-photodynamic therapy

Polymeric nanoparticles generated by mPEG-tetrakis(4-carboxyphenyl)porphyrin amphiphiles were used to trap doxorubicin for synergistic chemo-photodynamic therapy.

Nanostructured lipid carriers used for oral delivery of oridonin: an effect of ligand modification on absorption

Oridonin (Ori) is a natural compound with notable anti-inflammation and anti-cancer activities. However, therapeutic use of this compound is limited by its poor solubility and low bioavailability. Here a novel biotin-modified nanostructured lipid carrier (NLC) was developed to enhance the bioavailability of Ori. The effect of ligand (biotin) modification on oral absorption of Ori encapsulated in NLCs was also explored. Ori-loaded NLCs (Ori-NLCs) were prepared by the melt dispersion-high pressure homogenization method. Biotin modification of Ori-NLCs was achieved by EDC and NHS in aqueous phase. The obtained biotin-decorated Ori-NLCs (Bio-Ori-NLCs) were 144.9nm in size with an entrapment efficiency of 49.54% and a drug load of 4.81%. Oral bioavailability was enhanced by use of Bio-Ori-NLCs with a relative bioavailability of 171.01%, while the value of non-modified Ori-NLCs was improved to 143.48%. Intestinal perfusion showed that Ori solution unexpectedly exhibited a moderate permeability, indicating that permeability was not a limiting factor of Ori absorption. Ori could be rapidly metabolized that was the main cause of low bioavailability. However, there was a difference in the enhancement of bioavailability between Bio-Ori-NLCs and conventional NLCs. Although severe lipolyses happened both on Bio-Ori-NLCs and non-modified NLCs, the performance of Bio-Ori-NLCs in the bioavailability improvement was more significant. Overall, Bio-Ori-NLCs can further promote the oral absorption of Ori by a ligand-mediated active transport. It may be a promising carrier for the oral delivery of Ori.