Solid lipid nanoparticles modified with chitosan oligosaccharides for the controlled release of doxorubicin

Synthesis and Characterization of Slow-Release Chitosan Oligosaccharide Pyridine Schiff Base Copper Complexes with Antifungal Activity

Herein, a series of chitosan oligosaccharide copper complexes modified with pyridine groups (CPSx-Cu complexes) were successfully prepared via the Schiff base reaction and ion complexation reaction for slow-release fungicide. The structures of the synthesized derivatives were characterized via Fourier transform infrared spectroscopy and 1H and 13C nuclear magnetic resonance spectroscopy, and the unit configuration of the complexes was calculated using Gaussian software. The slow-release performance experiment demonstrated that the cumulative copper ion release rate of CPSx-Cu complexes was dependent on the type of substituents on the pyridine ring. Furthermore, the in vitro and in vivo antifungal activities of the CPSx-Cu complexes were investigated. At a concentration of 0.4 mg/mL, CPSx-Cu complexes completely inhibited the growth of Pythium vexans and Phytophthora capsici. Results indicated that CPSx-Cu complexes with slow-release ability exhibited better antifungal activity than thiodiazole-copper and copper sulfate basic. This study confirmed that combining chitosan oligosaccharide with bioactive pyridine groups and copper ions is an effective approach to further developing slow-release copper fungicides, providing new possibilities for the application of copper fungicides in green agriculture. This study lays the foundation for further studies on biogreen copper fungicides.

Preparation and characterization of the myricetin-loaded solid lipid nanoparticles decorated with folic acid-bound chitosan and evaluation of its antitumor and anti-angiogenic activities in vitro and in vivo in mice bearing tumor models

Myricetin is a flavonoid with anticancer properties. This study aimed to formulate myricetin in the form of solid lipid nanoparticles (SLN), decorated with chitosan (CS) and active-targeted with folic acid (FA). After characterization, the in vitro release, cytotoxicity, antioxidant, and ability of the formulation to induce apoptosis using flow cytometry, fluorescent microscopy, and real-time qPCR were examined. Then in vivo anti-angiogenesis on chick chorioallantoic membrane (CAM) and antitumor activities on mice bearing tumor models were investigated. The present study showed that the size of 310 nm and zeta potential of + 30 mV were acceptable for oral administration. The Michaelis–Menten model fitted the drug release pattern with lag during 144 h of the study. The cytotoxicity assay showed that myricetin-SLN-CS-FA significantly killed cancer cells at the concentrations of 6.25, 12.5, 25, 50 and 100 µg/mL (*p < 0.05, **p < 0.01, and ***p < 0.001). The highest level of apoptosis was shown at the concentration of 45 µg/ml in flow cytometry, and fluorescent studies. These results showed the anticancer properties of myricetin-SLN-CS-FA in a dose-dependent manner. The real-time results also indicated that the formulation exerted its cytotoxic effect by activating apoptosis genes. The DPPH, ABTS, and FRAP studies also demonstrated the significant antioxidant properties of the myricetin-SLN-CS-FA (*p < 0.05, **p < 0.01, and ***p < 0.001). The anti-angiogenic activities of the formulations depicted in the CAM assay significantly decrease the number and length of the vessels (*p < 0.05, **p < 0.01, and ***p < 0.001), and also affect VEGF and VEGFR, genes involved in angiogenesis (**p < 0.01, and ***p < 0.001). The antitumor studies indicated the statistically significant effects of myricetin-SLN-CS-FA on reducing tumor volume (*p < 0.05 and ***p < 0.001). The H&E staining of the liver and monitoring of the animal weights also indicated the safety of the formulation. The analysis of mRNA expression in liver and tumor demonstrated that myricetin-SLN-CS-FA exerts its antitumor activities by modulating the inflammatory and oxidative responses in the tissues.

Multifunctional targeted solid lipid nanoparticles for combined photothermal therapy and chemotherapy of breast cancer

Photothermal therapy has emerged as a new promising strategy for the management of cancer, either alone or combined with other therapeutics, such as chemotherapy. The use of nanoparticles for multimodal therapy can improve treatment performance and reduce drug doses and associated side effects. Here we propose the development of a novel multifunctional nanosystem based on solid lipid nanoparticles co-loaded with gold nanorods and mitoxantrone and functionalized with folic acid for dual photothermal therapy and chemotherapy of breast cancer. Nanoparticles were produced using an economically affordable method and presented suitable physicochemical properties for tumor passive accumulation. Upon Near-Infrared irradiation (808 nm, 1.7 W cm^-2, 5 min), nanoparticles could effectively mediate a temperature increase of >20 °C. Moreover, exposure to light resulted in an enhanced release of Mitoxantrone. Furthermore, nanoparticles were non-hemolytic and well tolerated by healthy cells even at high concentrations. The active targeting strategy was found to be successful, as shown by the greater accumulation of the functionalized nanoparticles in MCF-7 cells. Finally, the combined effects of chemotherapy, light-induced drug release and photothermal therapy significantly enhanced breast cancer cell death. Overall, these results demonstrate that the developed lipid nanosystem is an efficient vehicle for breast cancer multimodal therapy.

Targeted delivery and anticancer effects of Chrysin-loaded chitosan-folic acid coated solid lipid nanoparticles in pancreatic malignant cells

The aim of this survey was to load Chrysin (CHY) on solid lipid nanoparticles (SLNs) and decorate the nanoparticles with folate-bound chitosan to increase the effectiveness of the treatment. CHY-SCF-NPs were synthesized by homogenizing and sonication methods and characterized. FA binding and encapsulation efficiency (HPLC), antioxidant capacity (ABTS and DPPH), cell viability assay (MTT), programmed cell death analysis (fluorescence staining, flow cytometry, and qPCR), and angiogenesis (CAM and molecular analysis) assay were done for assessment of therapeutic efficiency of CHY-SCF-NPs. Increases in size and change in surface charge of CHY-SLNs (PS: 84.3 nm and ZP: -18 mV) were reported after coating with folate-bound chitosan (PS: 125 nm and ZP: +34.9 mV). CHY-SCF-NPs inhibited PANC, MCF-7, A2780, and HepG2 as malignant cells and HFF as normal cells with IC₅₀∼53, 55, 249, and >250 µg/mL, respectively. Also, CHY-SCF-NPs scavenged ABTS (IC₅₀: 123.73 µg/mL), and DPPH (IC₅₀: 108.7 µg/mL) free radicals and suppressed angiogenesis in the CAM and qPCR assays. Up-regulation of Bax and caspase 9 genes as well as the fluorescence staining and cell cycle results confirmed the pro-apoptotic properties of CHY-SCF-NPs. CHY-SCF-NPs can be considered a promising anti-cancer candidate for preclinical and clinical studies of pancreatic cancer.

Folic acid-Chitosan Coated Stylosin Nanostructured Lipid Carriers: Fabrication, In Vitro-In Vivo Assessment in Breast Malignant Cells

Synthesis of targeted nanostructure lipid carriers for stylosin (STY-CFN-NPs) delivery to MCF-7 cells. STY-CFN-NPs were formulated via the homogenization and ultra-sonication technique. After evaluating the amount of drug encapsulation and FA binding, the toxicity effect of the STY and STY-CFN-NPs on MCF-7 cells was measured by the MTT method. Cell cycle analysis, AO/PI staining and qPCR to assess the inducing of apoptosis as well as Tubo cancer cell inoculated mouse model for antitumor properties of STY-CFN-NPs were used. Significant increases in nanoparticle size and changes in zeta potential were observed after FA-CS coating on nanoparticles. Slow release of the STY within 144 h as well as the acceptable rate for STY encapsulation efficiency (92.4% and FA binding (52.5%) to the STY-CFN-NPs (PS: 66.26 ± 3.02 nm, ZP: 29.54 ± 1.01 mV and PDI: 0.32 ± 0.01) was reported. STY-CFN-NPs exhibited higher toxicity compared to STY suspension and treatment with STY-CFN-NPs was lead to increased apoptotic cells, stopped cells in the SubG1 phase, and also increased caspase and BAX expression and decreased BCL-2 and BCL-XL expression in in vitro and decreased the size of murine tumors (54.57% in 16 days) in in vivo. The results showed STY-CFN-NPs have good potential for breast cancer management.

Improved biopharmaceutical performance of antipsychotic drug using lipid nanoparticles via intraperitoneal route

This study aims to develop, characterize, and examine olanzapine-loaded solid lipid nanocarriers (OLAN-SLNs) for effective brain delivery. OLAN has poor water solubility and low penetration through blood-brain barrier (BBB). Herein, OLAN-SLNs were fabricated using high-pressure homogenization (HPH) method followed by their investigation for particle properties. Moreover, in vitro release and in vivo pharmacokinetics profiles of OLAN-SLNs were compared with pure drug. Anti-psychotic activity was performed in LPS-induced psychosis mice model. Furthermore, expressions of the COX-2 and NF-κB were measured trailed by histopathological examination. The optimized formulation demonstrated nanoparticle size (149.1 nm) with rounded morphology, negative zeta potential (-28.9 mV), lower PDI (0.334), and excellent entrapment efficiency (95%). OLAN-SLNs significantly retarded the drug release and showed sustained release pattern as compared to OLAN suspension. Significantly enhanced bioavailability (ninefold) was demonstrated in OLAN-SLNs when compared with OLAN suspension. Behavioral tests showed significantly less immobility and more struggling time in OLAN-SLNs treated mice group. Additionally, reduced expression of COX-2 and -NF κB in brain was found. Altogether, it can be concluded that SLNs have the potential to deliver active pharmaceutical ingredients to brain, most importantly to enhance their bioavailability and antipsychotic effect, as indicated for OLAN in this study.

Satureja khuzistanica Essential Oil-Loaded Solid Lipid Nanoparticles Modified With Chitosan-Folate: Evaluation of Encapsulation Efficiency, Cytotoxic and Pro-apoptotic Properties

The study aimed to synthesize Satureja khuzistanica essential oil-loaded SLN nanoparticles and to modify the surface of nanoparticles with folate-bound chitosan (SEO-SCF-NPs), and finally to investigate the effects of its toxicity and pro-apoptosis. For this purpose, the SEO-SLN nanoparticles were prepared using stearic acid, lecithin, tween 80, and water by high-pressure homogenization method. After characterization by FTIR, SEM, DLS, and ZETA potential methods, its toxicity effect against normal (HFF) and cancer (MCF-7) cells were evaluated by MTT assay. The occurrence of apoptosis in MCF-7 cells was assessed by flow cytometry and molecular analysis. The obtained results revealed the formation of round nanoparticles with a size of 279.40 nm, single dispersed (PDI: 0.3) and stable (ζ–potential: +31.69 mV). SEO-SCF-NPs indicated the effect of selective toxicity against MCF-7 cells (IC₅₀: 88 μg/ml). Molecular analysis showed that SEO-SCF-NPs could inhibit cancer cells by activating the internal pathway of apoptosis as well as cell cycle disruption. Our finding suggests that SEO-SCF-NPs is a suitable candidate for preclinical cancer studies.

Study of antimycobacterial, cytotoxic, and mutagenic potential of polymeric nanoparticles of copper (II) complex

This study aimed to encapsulate and characterize a potential anti-tuberculosis copper complex (CuCl₂(INH)₂.H₂O:I1) into polymeric nanoparticles (PNs) of polymethacrylate copolymers (Eudragit®, Eu) developed by nanoprecipitation method. NE30D, S100 and, E100 polymers were tested. The physicochemical characterizations were performed by DLS, TEM, FTIR, encapsulation efficiency and, in vitro release studies. Encapsulation of I1 in PN-NE30D, PN-E100, and PN-S100 was 26.3%, 94.5%, 22.6%, respectively. The particle size and zeta potential were 82.3 nm and -24.5 mV for PNs-NE30D, 304.4 nm and +18.7 mV for PNs-E100, and 517.9 nm and -6.9 mV for PNs-S100, respectively. All PDIs were under 0.5. The formulations showed a I1 controlled release at alkaline pH with 29.7% from PNs-NE30D, 7.9% from PNs-E100 and, 28.1% from PNs-S100 at 1 h incubation. PNs were stable for at least 3 months. Particularly, PNs-NE30D demonstrated moderate inhibition of M. tuberculosis and low cytotoxic activity. None of the PNs induced mutagenicity.

Chitosan films and scaffolds for regenerative medicine applications: A review

Over the last years, chitosan has demonstrated unparalleled characteristics for regenerative medicine applications. Beside excellent antimicrobial and wound healing properties, this polysaccharide biopolymer offers favorable characteristics such as biocompatibility, biodegradability, and film and fiber-forming capabilities. Having plentiful active amine groups, chitosan can be also readily modified to provide auxiliary features for growing demands in regenerative medicine, which is constantly confronted with new problems, necessitating the creation of biocompatible, immunogenic and biodegradable film/scaffold composites. A new look at the chitosan composites structure/activity/application tradeoff is the primary focus of the current review, which can help researchers to detect the bottlenecks and overcome the shortcomings that arose from this intersection. In the current review, the most recent advances in chitosan films and scaffolds in terms of preparation techniques and modifying methods for improving their functional properties, in three major biomedical fields i.e., tissue engineering, wound healing, and drug delivery are surveyed and discussed.

Improved Bioavailability of Poorly Soluble Drugs through Gastrointestinal Muco-Adhesion of Lipid Nanoparticles

Gastrointestinal absorption remains indispensable in the systemic delivery of most drugs, even though it presents several challenges that, paradoxically, may also provide opportunities that can be exploited to achieve maximal bioavailability. Drug delivery systems made from nanoparticle carriers and especially, lipid carriers, have the potential to traverse gastrointestinal barriers and deploy in the lymphatic pathway, which aptly, is free from first pass via the liver. Several poorly soluble drugs have presented improved systemic bioavailability when couriered in lipid nanoparticle carriers. In this review, we propose an additional frontier to enhancing the bioavailability of poorly soluble drugs when encapsulated in lipid nano-carriers by imparting muco-adhesion to the particles through application of appropriate polymeric coating to the lipid carrier. The combined effect of gastrointestinal muco-adhesion followed by lymphatic absorption is a promising approach to improving systemic bioavailability of poorly soluble drugs following oral administration. Evidence to the potential of this approach is backed-up by recent studies within the review.

Mitoxantrone-loaded lipid nanoparticles for breast cancer therapy - Quality-by-design approach and efficacy assessment in 2D and 3D in vitro cancer models

Breast cancer is the leading cause of cancer-related deaths among women worldwide. The conventional chemotherapeutic regimens used in the treatment of this disease often lead to severe side-effects and reduced efficacy. In this study, a novel drug delivery system for the chemotherapeutic drug mitoxantrone (Mito) was developed using solid lipid nanoparticles (SLN). The production of the SLN was carried out using an organic-solvent-free, low-cost method and optimized using a Box-Behnken design. SLN presented adequate size for cancer-related applications, more than 90% of EE% and remained stable for at least 6 months. A much higher drug release was obtained at acidic pH (mimicking the endosomal compartment) than plasmatic pH, highlighting the potential of the nanosystem for tumor drug delivery. Additionally, SLN were non-hemolytic and cytocompatible, even at high concentrations of lipid. A significantly higher anti-cancer efficacy was obtained for Mito-loaded SLN comparing to the free drug at different concentrations in MCF-7 2D models. Finally, the nanoformulation was evaluated in heterotypic breast cancer spheroids showing capacity to penetrate the tridimensional structure and ability to induce a high anti-tumoral effect, similarly to the free drug. Overall, these results support that the developed SLN are effective Mito nanocarriers for the treatment of breast cancer.

Advanced nanomedicine approaches applied for treatment of skin carcinoma

Skin-cancer is the commonest malignancy affecting huge proportion of the population, reaching heights in terms of morbidity. The treatment strategies are presently focusing on surgery, radiation and chemotherapy, which eventually cause destruction to unaffected cells. To overcome this limitation, wide range of nanoscaled materials have been recognized as potential carriers for delivering selective response to cancerous cells and neoplasms. Nanotechnological approach has been tremendously exploited in several areas, owing to their functional nanometric dimensions. The alarming incidence of skin cancer engenders burdensome effects worldwide, which is further awakening innovational medicinal approaches, accompanying target specific drug delivery tools for coveted benefits to provide reduced toxicity and tackle proliferative episodes of skin cancer. The developed nanosystems for anti-cancer agents include liposomes, ethosomes, nanofibers, solid lipid nanoparticles and metallic nanoparticles, which exhibit pronounced outcomes for skin carcinoma. In this review, skin cancer with its sub-types is explained in nutshell, followed by compendium of specific nanotechnological tools presented, in addition to therapeutic applications of drug-loaded nano systems for skin cancer.

The Complexity of the Blood-Brain Barrier and the Concept of Age-Related Brain Targeting: Challenges and Potential of Novel Solid Lipid-Based Formulations

Diseases that affect the Central Nervous System (CNS) are one of the most exciting challenges of recent years, as they are ubiquitous and affect all ages. Although these disorders show different etiologies, all treatments share the same difficulty represented by the Blood-Brain Barrier (BBB). This barrier acts as a protective system of the delicate cerebral microenvironment, isolating it and making extremely arduous delivering drugs to the brain. To overtake the obstacles provided by the BBB it is essential to explore the changes that affect it, to understand how to exploit these findings in the study and design of innovative brain targeted formulations. Interestingly, the concept of age-related targeting could prove to be a winning choice, as it allows to consider the type of treatment according to the different needs and peculiarities depending on the disease and the age of onset. In this review was considered the prospective contribution of lipid-based formulations, namely Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), which have been highlighted as able to overcome some limitations of other innovative approaches, thus representing a promising strategy for the non-invasive specific treatment of CNS-related diseases.

Novel Curcumin-Resveratrol Solid Nanoparticles Synergistically Inhibit Proliferation of Melanoma Cells

Polyphenols such as curcumin (Cur) and resveratrol (Res) have been recently shown to have potential to inhibit proliferation of highly aggressive melanoma cells. This study was designed to investigate the feasibility of a topical delivery system, using a solid lipid nanoparticles (SLNs) loaded delivery systems, that can enhance the skin penetration and anti-cancer efficacy of combination of these polyphenols. Negatively charged Cur-Res SLNs with a mean diameter of 180.2 ± 7.7 nm were prepared using high shear homogenization method. Cur-Res SLNs were found to be stable up to 2 weeks under 4°C. The in vitro release study showed that Res was released five time more than curcumin. The permeability of resveratrol was about 1.67 times that of curcumin from the SLN-gel formulation which was significantly (p < 0.05) lower than from SLN suspension. More than 70% of Cur-Res SLNs were bound to skin locally in a skin binding study suggesting potentially utility of Cur-Res SLNs in the treatment of localized melanoma. In fact, the electrical cell-substrate impedance sensing (ECIS) measurements suggested that Cur-Res combination has potential to stop cell migration of B16F10 melanoma cells. Furthermore, both, Cur-Res SLNs and Cur-Res solution at the ratio of 3:1 demonstrated a strong synergistic inhibition of SK-MEL-28 melanoma cell proliferation. Further evaluation of Cur-Res SLNs in vivo melanoma models are warranted to establish the clinical utility of Cur-Res formulations in melanoma therapy.

Loading of doxorubicin on poly(methyl methacrylate-co-methacrylic acid) nanoparticles and release study

Nanoparticles (NP) of 12.7 nm in diameter of the poly(methyl methacrylate (MMA)-co-methacrylic acid (MAA)) copolymer were prepared. ¹³C-NMR results showed a MMA:MAA molar ratio of 0.64:0.36 in the copolymer, which is similar to the poly(MMA-co-MAA) commercially known as the FDA approved Eudragit S100 (0.67:0.33). The NP prepared in this study were loaded at pH 5 with varying amounts (from 0.54 to 6.91%) of doxorubicin (DOX), an antineoplastic drug. ¹H-NMR results indicated the electrostatic interactions between the ionized carboxylic groups of the MAA units in the copolymer and the proton of the glycosidic amine in DOX. Measurements by QLS and TEM indicated that the loading destabilizes the NP, and that for increase stability, they aggregate in a reversible way, forming aggregates with a diameter up to 99.5 nm at a DOX load of 6.91%. The analysis of drug release data at pH 7.4 showed that loaded NP with at least 4.38% DOX release the drug very slowly and follows the Higuchi model; the former suggests that they could remain for long periods in the bloodstream to reach and destroy cancer cells.

Particle and Gel Characterization of Irinotecan-Loaded Double-Reverse Thermosensitive Hydrogel

The irinotecan-loaded double-reverse thermosensitive hydrogel (DRTH) is a dispersed system of irinotecan-loaded solid lipid nanoparticles (SLN) in a thermosensitive hydrogel. To optimise the particle and gel properties of DRTHs for rectal administration of irinotecan, SLNs and DRTHs were prepared with tricaprin, triethanolamine, Tween 80, and Span 20. Among the SLNs tested, an SLN composed of 1 g irinotecan, 0.5 g lipid mixture, and 0.5 g combined surfactant gave the highest entrapment efficiency and smallest particle size. A DRTH composed of (poloxamer 407/poloxamer 188/combined surfactant/SLN dispersion/H₂O (10/15/17/4/54%)) showed easy administration, fast gelling, and strong gel-forming in the body.

Pectin co-functionalized dual layered solid lipid nanoparticle made by soluble curcumin for the targeted potential treatment of colorectal cancer

The investigation is to increase the cytotoxicity of soluble curcumin (SC) by loading it onto pectin and skimmed milk powder (SMP) dual layered solid lipid nanoparticles (DL-SLN). The DL-SLN exhibited significantly higher encapsulation efficiency (83.94 ± 6.16), better stability (90 days), and sustained the drug release in different gastro intestional (GI) environments upto 72 h. Molecular docking revealed that the Vander Waals (57420.669 Kcal^-mol^-1) and electrostatic (-197.533) bonds were involved in the DL-SLN complex formation. The in vivo toxicity of DL-SLN was performed by the zebrafish model, the cell cycle arrest at G₂/M phase (64.34 %) by flow cytometry, and western blot investigation was recognized molecular level cell death using SW480 cells. Pharmacokinetic (PK) evaluation (Cmax-5.78 ± 3.26 μg/mL; Tmax-24 h) and organ distribution studies confirmed that the co-functionalized pectin based SLN could efficiently improve the oral bioavailability (up to 72 h) of curcumin (CMN) on colon-targeted release.

Chitosan: Structural modification, biological activity and application

Many by-products that are harmful to the environment and human health are generated during food processing. However, these wastes are often potential resources with high-added value. For example, crustacean waste contains large amounts of chitin. Chitin is one of the most abundant polysaccharides in natural macromolecules, and is a typical component of crustaceans, mollusks, insect exoskeleton and fungal cell walls. Chitosan is prepared by deacetylation of chitin and a copolymer of D-glucosamine and N-acetyl-D-glucosamine through β-(1 → 4)-glycosidic bonds. Chitosan has better solubility, biocompatibility and degradability compared with chitin. This review introduces the preparation, physicochemical properties, chemical and physical modification methods of chitosan, which could help us understand its biological activities and applications. According to the latest reports, the antibacterial activity, antioxidant, immune and antitumor activities of chitosan and its derivatives are summarized. Simultaneously, the various applications of chitosan and its derivatives are reviewed, including food, chemical, textile, medical and health, and functional materials. Finally, some insights into its future potential are provided, including novel modification methods, directional modification according to structure-activity relationship, activity and application development direction, etc.

Focal drug administration via heparin-containing cryogel microcarriers reduces cancer growth and metastasis

Developing drug delivery systems that release anticancer drugs in a controlled and sustained manner remains challenging. We hypothesized that highly sulfated heparin-based microcarriers would allow electrostatic drug binding and controlled release. In silico modelling showed that the anticancer drug doxorubicin has affinity for the heparin component of the microcarriers. Experimental results showed that the strong electrostatic interaction was reversible, allowing both doxorubicin loading and a subsequent slow release over 42 days without an initial burst release. The drug-loaded microcarriers were able to reduce cancer cell viability in vitro in both hormone-dependent and highly aggressive triple-negative human breast cancer cells. Focal drug treatment, of an in vivo orthotopic triple-negative breast cancer model significantly decreased tumor burden and reduced cancer metastasis, whereas systemic administration of an equivalent drug dose was ineffective. This study proves that heparin-based microcarriers can be used as drug delivery platforms, for focal delivery and sustained long-term drug release.

Development of levosulpiride-loaded solid lipid nanoparticles and their in vitro and in vivo comparison with commercial product

The aim of this study was to develop levosulpiride-loaded solid lipid nanoparticles (SLNs) with enhanced solubilisation and bioavailability. The levosulpiride loaded-SLNs were composed of levosulpiride, stearic acid, and tween 80 in their respective weight ratios of (1, 5, and 1.5 mg) dissolved in 1 ml distilled water. Physicochemical properties of the SLNs such as particle size, shape, crystallinity, and chemical interaction were evaluated. Further, the in vitro drug dissolution, pharmacokinetic and stability studies of the SLNs were performed. The SLNs were rounded shaped stable nanoparticles with average diameter of 200 nm. They demonstrate 1.5- and 3-fold better drug dissolution when compared with the commercial product and levosulpiride powder, respectively. The SLNs enhanced the bioavailability of levosulpiride 3 times and 7 times, respectively, when compared with the commercial product and levosulpiride powder. It can be concluded that SLNs are capable to improve the dissolution and bioavailability of levosulpiride, even more than the commercial product.

Progress and perspectives of brain-targeting lipid-based nanosystems via the nasal route in Alzheimer's disease

Since health care systems dedicate substantial resources to Alzheimer's disease (AD), it poses an increasing challenge to scientists and health care providers worldwide, especially that many decades of research in the medical field revealed no optimal effective treatment for this disease. The intranasal administration route seems to be a preferable route of anti-AD drug delivery over the oral one as it demonstrates an ability to overcome the related obstacles reflected in low bioavailability, limited brain exposure and undesired pharmacokinetics or side effects. This delivery route can bypass the systemic circulation through the intraneuronal and extraneuronal pathways, providing truly needleless and direct brain drug delivery of the therapeutics due to its large surface area, porous endothelial membrane, the avoidance of the first-pass metabolism, and ready accessibility. Among the different nano-carrier systems developed, lipid-based nanosystems have become increasingly popular and have proven to be effective in managing the common symptoms of AD when administered via the nose-to-brain delivery route, which provides an answer to circumventing the BBB. The design of such lipid-based nanocarriers could be challenging since many factors can contribute to the quality of the final product. Hence, according to the authors, it is recommended to follow the quality by design methodology from the early stage of development to ensure high product quality while saving efforts and costs. This review article aims to draw attention to the up-to-date findings in the field of lipid-based nanosystems and the potential role of developing such forms in the management of AD by means of the nose-to-brain delivery route, in addition to highlighting the significant role of applying QbD methodology in this development.

Pharmacokinetic Evaluation of 99mTc-radiolabeled Solid Lipid Nanoparticles and Chitosan Coated Solid Lipid Nanoparticles

BACKGROUND

Solid Lipid Nanoparticles (SLNs) possess unique in vivo features such as high resistivity, bioavailability, and habitation at the target site. Coating nanoparticles with polymers such as chitosan greatly affects their pharmacokinetic behavior, stability, tissue uptake, and controlled drug delivery. The aim of this study was to prepare and evaluate the biodistribution of 99mTc-labeled SLNs and chitosan modified SLNs in mice.

METHODS

99mTc-oxine was prepared and utilized to radiolabel pre-papered SLNs or chitosan coated SLNs. After purification of radiolabeled SLNs (99mTc-SLNs) and radiolabeled chitosan-coated SLNs (99mTc-Chi-SLNs) using Amicon filter, they were injected into BALB/c mice to evaluate their biodistribution patterns. In addition, nanoparticles were characterized using Transmission Electron Microscopy (TEM), Fourier-transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Powder Diffraction (XRD) and Dynamic Light Scattering (DLS).

RESULTS

99mTc-oxine with high radiochemical purity (RCP~100%) and stability (RCP > 97% at 24 h) was used to provide 99mTc-SLNs and 99mTc-Chi-SLNs with high initial RCP (100%). TEM image and DLS data suggest 99mTc- SLNs susceptibility to aggregation. To that end, the main portion of 99mTc-SLNs radioactivity accumulates in the liver and intestines, while 99mTc-Chi-SLNs sequesters in the liver, intestines and kidneys. The blood radioactivity of 99mTc-Chi-SLNs was higher than that of 99mTc-SLNs by 7.5, 3.17 and 3.5 folds at 1, 4 and 8 h post-injection. 99mTc- Chi-SLNs uptake in the kidneys in comparison with 99mTc-SLNs was higher by 37.48, 5.84 and 11 folds at 1, 4 and 8h.

CONCLUSION

The chitosan layer on the surface of 99mTc-Chi-SLNs reduces lipophilicity in comparison with 99mTc- SLNs. Therefore, 99mTc-Chi-SLNs are less susceptible to aggregation, which leads to their lower liver uptake and higher kidney uptake and blood concentration.

Comparison of different aliphatic acid grafted N-trimethyl chitosan surface-modified nanostructured lipid carriers for improved oral kaempferol delivery

This study compared the in vitro and in vivo effects of different aliphatic acid grafted N-trimethyl chitosan (TMC) surface-modified nanostructured lipid carriers (NLC) by oral delivery. Medium-chain fatty acids, decylic acids (DA), and long-chain fatty acids, palmitic acids (PA) were selected as contrasting objects. TMC, DA grafted TMC (DA-TMC), and PA grafted TMC (PA-TMC) were successively synthesized. Kaempferol loaded NLC (KNLC), KNLC coated with DA-TMC (DA-TMC-KNLC) and PA-TMC (PA-TMC-KNLC) were fabricated, respectively. KNLC were subspherical in shape at nano-size limits. The particle size increased from 93.6 to 125.5 nm and the zeta potential changed from negative to positive due to surface-modification. The KNLC surface-modified with different aliphatic acid grafted TMC displayed a diverse release profiles at the simulative physiological environment, which contrasted that of KNLC. Pharmacokinetic studies demonstrated that the nanoparticles all could improve the AUC values and prolong blood retention times compared to that of kaempferol suspensions. Cell uptake and in situ intestinal perfusion experiments revealed that DA-TMC-KNLC and PA-TMC-KNLC could remarkably enhance cellular uptake of kaempferol into Caco-2 cells and drug absorption in each intestinal segment in comparison with KNLC, repectively. Wherein, DA-TMC-KNLC exhibits the greatest uptake and absorption efficiency as compared to kaempferol suspensions, KNLC and PA-TMC-KNLC. Collectively, DA-TMC surface-modified NLC might serve as a potential drug carrier for oral delivery of water-insoluble flavonoid ingredients.

Antifungal and Mucoadhesive Properties of an Orally Administered Chitosan-Coated Amphotericin B Nanostructured Lipid Carrier (NLC)

Surface-modified nanostructured lipid carriers (NLC) represent a promising mode of drug delivery used to enhance retention of drugs at absorption site. Formulated chitosan-coated amphotericin-B-loaded NLC (ChiAmp NLC) had a size of 394.4 ± 6.4 nm, encapsulation and loading efficiencies of 86.0 ± 3% and 11.0 ± 0.1% respectively. Amphotericin-B release from NLCs was biphasic with no changes in physical properties upon exposure to simulated gastrointestinal conditions. Antifungal properties of Amphotericin-B and ChiAmpB NLC were comparable but ChiAmpB NLC was twice less toxic to red blood cells and ten times safer on HT-29 cell lines. In vitro mucoadhesion data were observed ex vivo, where ChiAmpB NLC resulted in higher retention within the small intestine compared to the uncoated formulation. The data strongly offers the possibility of orally administering a non-toxic, yet effective Amphotericin-B nanoformulation for the treatment of systemic fungal infections.

A review on the efficacy and toxicity of different doxorubicin nanoparticles for targeted therapy in metastatic breast cancer

In metastatic breast cancer (MBC), the conventional doxorubicin (DOX) has various problems due to lack of selectivity with subsequent therapeutic failure and adverse effects. DOX- induced cardiotoxicity is a major problem that necessitates the presence of new forms to decrease the risk of associated morbidity. Nanoparticles (NPs) are considered an important approach to selectively increase drug accumulation inside tumor cells and thus decreasing the associated side effects. Tumor cells develop resistance to chemotherapeutic agents through multiple mechanisms, one of which is over expression of efflux transporters. Various NPs have been investigated to overcome efflux mediated resistance. To date, only liposomal doxorubicin (LD) and pegylated liposomal doxorubicin (PLD) have entered phase II and III clinical trials and FDA- approved for clinical use in MBC. This review addresses the effects of LD and PLD on the hematological and palmar-plantar erythrodysesthesia (PPE) in anthracycline naïve and pretreated MBC patients. For evidence, studies to be included in this review were identified through PubMed, Cochrane and Google scholar databases. The results derived from: four phase III clinical trials that compared LD with the conventional DOX in naïve MBC patients, and ten non-comparative clinical trials investigated LD and PLD as monotherapy or combination in pretreated MBC. This work confirmed the cardiac tolerability profile of LD and PLD versus DOX, while hematological and skin toxicities were more common. Other DOX-NPs in preclinical trials were discussed in a chronological order. Finally, the modern preclinical development framework for DOX includes exosomal DOX (exo-DOX). Exosomal NPs are non-toxic, non-immunogenic, and can be engineered to have high cargo loading capacity and targeting specificity. These NPs have not been investigated clinically. Our study shows that the full clinical potentiality of DOX-NPs remains to be addressed to move the field forward.

Synthetic surfactant- and cross-linker-free preparation of highly stable lipid-polymer hybrid nanoparticles as potential oral delivery vehicles

The toxicity associated with concentrated synthetic surfactants and the poor stability at gastrointestinal condition are two major constraints for practical applications of solid lipid nanoparticles (SLN) as oral delivery vehicles. In this study, a synthetic surfactant-free and cross-linker-free method was developed to fabricate effective, safe, and ultra-stable lipid-polymer hybrid nanoparticles (LPN). Bovine serum albumin (BSA) and dextran varying in molecular weights were first conjugated through Maillard reaction and the conjugates were exploited to emulsify solid lipid by a solvent diffusion and sonication method. The multilayer structure was formed by self-assembly of BSA-dextran micelles to envelope solid lipid via a pH- and heating-induced facile process with simultaneous surface deposition of pectin. The efficiency of different BSA-dextran conjugates was systematically studied to prepare LPN with the smallest size, the most homogeneous distribution and the greatest stability. The molecular interactions were characterized by Fourier transform infrared and fluorescence spectroscopies. Both nano spray drying and freeze-drying methods were tested to produce spherical and uniform pectin-coated LPN powders that were able to re-assemble nanoscale structure when redispersed in water. The results demonstrated the promise of a synthetic surfactant- and cross-linker-free technique to prepare highly stable pectin-coated LPN from all natural biomaterials as potential oral delivery vehicles.

Irinotecan-loaded double-reversible thermogel with improved antitumor efficacy without initial burst effect and toxicity for intramuscular administration

Intramuscularly administered, anti-tumour drugs induce severe side effects due to their direct contact with body tissues and initial burst effect. In this study, to solve this problem, a novel double-reversible thermogel system (DRTG) for the intramuscular administration of irinotecan was developed. This irinotecan-loaded DRTG was prepared by dispersing the irinotecan-loaded thermoreversible solid lipid nanoparticles (SLNs) in the thermoreversible hydrogel. In DRTG, the former was solid at 25°C but converted to liquid at 36.5°C; in contrast, the latter existed in a liquid form but transformed to gel state in the body. The DRTG was easily administered intramuscularly. Its particle size and drug content were not noticeably changeable, resulting that it was stable at 40°C for at least 6months. Compared to the irinotecan-loaded solution and conventional hydrogel, the DRTG significantly delayed drug release, leading to a reduced burst effect. Moreover, it showed decreased C_max and maintained the sustained plasma concentrations at a relatively low level for the long period of 60h in rats, resulting in ameliorated side effects of the anti-tumour drug. Furthermore, it gave significantly improved anti-tumour efficacy in tumour-bearing mice compared to the hydrogel but, unlike the conventional hydrogel, induced no body weight loss and local damage to the muscle. Thus, this DRTG with improved antitumor efficacy without initial burst effect and toxicity could provide a potential pharmaceutical system for the intramuscular administration of irinotecan.

STATEMENT OF SIGNIFICANCE

Intramuscularly administered, anti-tumour drugs induce severe side effects due to their direct contact with body tissues and initial burst effect. To solve this problem, we developed a novel double-reversible thermogel system (DRTG) for the intramuscular administration of irinotecan. Unlike the conventional hydrogel, the DRTG is a dispersion of the irinotecan-loaded thermoreversible solid lipid nanoparticles in the thermoreversible hydrogel. In DRTG, the former was solid at 25°C but converted to liquid at 36.5°C; in contrast, the latter existed in a liquid form but transformed to gel state in the body. This DRTG gave significantly improved anti-tumour efficacy in tumour-bearing mice compared to the hydrogel but, unlike the conventional hydrogel, induced no body weight loss and local damage to the muscle.

Assessing safety and protein interactions of surface-modified iron oxide nanoparticles for potential use in biomedical areas

We have investigated the electrostatic interaction between bare iron oxide nanoparticles (IONPs) or low molecular weight chitosan coated iron oxide nanoparticles (LMWC-IONPs) and hen egg white lysozyme (HEWL) at different pH values using protein-nanoparticle reverse charge parity model. Physicochemical characterization of both IONPs and LMWC-IONPs were carried out using DLS, TEM, FE-SEM, XRD, TGA, XPS and VSM analysis. DLS, TEM and FE-SEM results indicated that both IONPs were monodispersed, with size ranging from 8 to 20nm. The coating of LMWC on IONPs was confirmed using zeta potential, TGA, XRD and XPS measurements. The cytotoxicity of both IONPs and LMWC-IONPs was studied in vitro in A549 human lung alveolar epithelial cells to assess their use in biomedical applications. Furthermore, the interactions between protein-nanoparticles were investigated by UV-visible, fluorescence and circular dichroism spectroscopic techniques. The present study suggests that water soluble LMWC surface modified IONPs are the promising nanomaterials. The safety and biocompatibility of these nanoparticles render them suitable for biomedical applications.

Surface modification of nanostructure lipid carrier (NLC) by oleoyl-quaternized-chitosan as a mucoadhesive nanocarrier

A nanostructure lipid carrier (NLC) composed of solid, and liquid lipid as a core has been developed as a delivery system for hydrophobic drug molecules. The aim of this research was to fabricate an oleoyl-quaternized-chitosan (CS)-coated NLC, where the mucoadhesive property of nanoparticles is enhanced for more efficient drug delivery. NLC loaded with alpha-mangostin (AP), a model hydrophobic drug, were fabricated using a high pressure homogenization process and subsequently coated with CS. The fabricated nanoparticles showed particle sizes in the range of 200-400nm, with low polydispersity, high physical stability and excellent encapsulation efficiency (EE>90%). Additionally, in vitro viability, cytotoxicity and ability of NLC and CS-NLC to affect apoptosis in carcinoma Caco-2 cells were determined using the Triplex assay. Gene expressiom analysis were performed using quantitative reverse transcription Polymerase Chain Reaction (RT-qPCR). Moreover, in vivo toxicological testing of NLCs was conducted in zebrafish embryos. Results indicated that CS-NLC provieded high cytotoxicity than NLC itself. In the case of AP loaded nanoparticles, NLC loaded with AP (AP-NLC), and CS-NLC loaded with AP (CS-AP-NLC) exhibited higher cytotoxicity to Caco-2 over Hela cells. These results indicate that CS-NLC shows enhanced cellular uptake but increased cytotoxicity characteristics over NLC and therefore careful optimization of dosage and loading levels in CS-NLC is needed to allow cancer cell targeting, and for exploiting the potential of these systems in cancer therapy.

Solid lipid nanoparticles coated with cross-linked polymeric double layer for oral delivery of curcumin

Solid lipid nanoparticles (SLNs) are regarded as promising carriers to improve the safety and effectiveness of delivery for drugs and nutrients, however, the clinic applications for oral administration are limited by their poor stability in gastrointestinal conditions. In this study, surface modification was explored to confer new physicochemical properties to SLNs and thus achieve enhanced functionalities. Novel SLNs with biopolymeric double layer (DL) coating using two natural biopolymers, i.e. caseinate (NaCas) and pectin, were prepared to encapsulate and deliver curcumin, a lipophilic bioactive compound studied as a model drug/nutrient. The DL coating was chemically cross-linked by creating covalent bonds between NaCas and pectin, using two different cross-linkers, i.e. glutaraldehyde (GA) and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-Hydroxysuccinimide (EDC/NHS). Prior to cross-linking, the mean particle size, polydispersity index and zeta potential of DL-SLNs were 300-330nm, 0.25-0.30, -45-40mV, respectively. It was found that cross-linking with GA had a more prominent effect on particle size and polydispersity index than EDC/NHS. The cross-linking process significantly improved physicochemical properties of DL-SLNs, resulting in higher encapsulation efficiency and loading capacity, better stability and slower release profile in simulated gastrointestinal conditions. Particularly, an optimal zero-order release kinetic was observed for EDC/NHS crosslinked DL-SLNs. The electron microscopy revealed that both cross-linked DL-SLNs exhibited spherical shape with homogeneous size and smooth surface. Encapsulation of curcumin in SLNs dramatically enhanced its antioxidant activity in aqueous condition. The cross-linking process further helped spray drying of SLNs by forming homogenous powder particles. These results indicated that coating with cross-linked polymers could significantly improve the physicochemical properties of SLNs and expand their potentials as oral delivery systems for lipophilic nutrients and drugs.

Solid lipid nanoparticles as attractive drug vehicles: Composition, properties and therapeutic strategies

This work briefly reviews up-to-date developments in solid lipid nanoparticles (SLNs) as effective nanocolloidal system for drug delivery. It summarizes SLNs in terms of their preparation, surface modification and properties. The application of SLNs as a carrier system enables to improve the therapeutic efficacy of drugs from various therapeutic groups. Present uses of SLNs include cancer therapy, dermatology, bacterial infections, brain targeting and eye disorders among others. The usage of SLNs provides enhanced pharmacokinetic properties and modulated release of drugs. SLN ubiquitous application results from their specific features such as possibility of surface modification, increased permeation through biological barriers, resistance to chemical degradation, possibility of co-delivery of various therapeutic agents or stimuli-responsiveness. This paper will be useful to the scientists working in the domain of SLN-based drug delivery systems.

Recent Progress in Chitosanase Production of Monomer-Free Chitooligosaccharides: Bioprocess Strategies and Future Applications

Biological activities of chitosan oligosaccharides (COS) are well documented, and numerous reports of COS production using specific and non-specific enzymes are available. However, strategies for improving the overall yield by making it monomer free need to be developed. Continuous enzymatic production from chitosan derived from marine wastes is desirable and is cost-effective. Isolation of potential microbes showing chitosanase activity from various ecological niches, gene cloning, enzyme immobilization, and fractionation/purification of COS are some areas, where lot of work is in progress. This review covers recent measures to improve monomer-free COS production using chitosanase/non-specific enzymes and purification/fractionation of these molecules using ultrafiltration and column chromatographic techniques. Various bioprocess strategies, gene cloning for enhanced chitosanase enzyme production, and other measures for COS yield improvements have also been covered in this review. COS derivative preparation as well as COS-coated nanoparticles for efficient drug delivery are being focused in recent studies.

Exploitation of lipid-polymeric matrices at nanoscale for drug delivery applications

INTRODUCTION

Progress in drug delivery and a better quality of life for patients, relies on the development of new and suitable drug carrier systems, with unequivocal therapeutic benefits, low systemic toxicity and reduced side effects. Lipid-polymeric nanoparticles have been explored to produce nanocarriers due to their features and applications such as high drug entrapment, physical-chemical stability and controlled release properties.

AREAS COVERED

In this review, we describe several hybrid nanoparticles obtained from mixing a polymer with a lipid matrix. This association can potentiate the efficacy of drug delivery systems, due to the enhancement of encapsulation efficiency and loading capacity, tailoring the drug release according to the therapeutic purpose, and improving the drug uptake by targeting it to specific receptors. Contrary to lipid nanoparticles, these hybrid nanoparticles can decrease the initial burst release and promote a more sustained and localized release of the drug.

EXPERT OPINION

Lipid-polymeric nanoparticles are versatile vehicles for drug delivery by different administration routes in the treatment of multiple diseases. Different solid lipids, polymers, surfactants and techniques for producing these carriers have been investigated, revealing the importance of their composition to achieve optimal characteristics to drug delivery.

Metal ion-assisted drug-loading model for novel delivery system of cisplatin solid lipid nanoparticles with improving loading efficiency and sustained release

Metal ion-assisted drug loading model, in which metal ion was used to modify the microstructure of lipid layer, has been developed to improve drug loading efficiency of solid lipid nanoparticles (SLNs). The microstructure and properties of metal ion-assisted cisplatin-loading SLNs were investigated by infra-red spectroscopy, fluorescence spectroscopy and zetasizer. The reactions of hydrogenated soybean lecithin with Zn(2+), Cu(2+), Mn(2+ )and Mg(2+ )have been detected; the mechanism for higher drug encapsulation efficiency (EE) has been investigated. In metal ion introduction SLNs, the compact degree of the lipid molecules was increased due to the electrostatic interaction between metal ions and phospholipid acyl and choline polarity groups, which result in increasing of drug EE. Meanwhile, these electrostatic interactions slowed the releasing rate of encapsulated drug. The study of cytotoxic activity in vitro indicated that the cell cytotoxicity of metal ions introduction SLNs depended on both cell uptake of SLNs and drug releasing from SLNs.

Development and characterization of a novel lipohydrogel nanocarrier: repaglinide as a lipophilic model drug

Objectives

Solid lipid nanoparticles (SLNs) are highly susceptible to phagocytosis by reticuloendothelial system (RES). To overcome this problem, a novel hydrogel-coated SLNs structure was developed and evaluated in this study.

Methods

Solid lipid nanoparticles surface was coated with chitosan, via electrostatic attraction with the negatively charged SLNs surface. The resulting polymer-coated SLNs then hosted an inorganic poly-anionic agent, tripolyphosphate, to form the final lipohydrogel structure.

Key findings

Compared with the bare SLNs, lipohydrogel nanoparticles (LHNs) showed a significant increase in size and zeta potential. The release profile showed lower burst release and lower release rate for LHNs compared with SLNs. LHNs nanoparticles released the model antidiabetic drug, repaglinide, in a more sustained manner with lower burst effect compared with the corresponding SLN structure. Cytotoxicity studies via cell culture and MTT assay revealed no bio-toxicity of the SLNs and LHNs. In addition, intravenous administration of repaglinide-loaded SLNs and LHNs in rats showed longer drug residence time in circulation for LHNs, a trend also evident for the blood glucose level-time profile.

Conclusion

The particle size, zeta potential, FTIR and microscopy data demonstrated the formation of the supposed lipohydrogel nanoparticles. All these benefits of LHNs propose it as a promising candidate for controlled release of the drugs.

Transport Mechanisms of Solid Lipid Nanoparticles across Caco-2 Cell Monolayers and their Related Cytotoxicology

Solid lipid nanoparticles (SLNs) have been extensively investigated and demonstrated to be a potential nanocarriers for improving oral bioavailability of many drugs. However, the molecular mechanisms related to this discovery are not yet understood. Here, the molecular transport mechanisms of the SLNs crossing simulative intestinal epithelial cell monolayers (Caco-2 cell monolayers) were studied. The cytotoxicology results of the SLNs in Caco-2 cells demonstrated that the nanoparticles had low cytotoxicity, had no effect on the integrity of the cell membrane, did not induce oxidative stress, and could significantly reduce cell membrane fluidity. The endocytosis of the SLNs was time-dependent, and their delivery was energy-dependent. For the first time, the transport of the SLNs was directly verified to be a vesicle-mediated process. The internalization of the SLNs was mediated by macropinocytosis pathway and clathrin- and caveolae (or lipid raft)-related routes. Transferrin-related endosomes, lysosomes, endoplasmic reticulum (ER), and Golgi apparatus were confirmed to be the main destinations of the SLNs in Caco-2 cells. As for the transport of the SLNs in Caco-2 cell monolayers, the results demonstrated that the SLNs transported to the basolateral side were intact, and the transport of the nanoparticles did not destroy the structure of tight junctions. The transcytosis of the SLNs across the Caco-2 cell monolayer was demonstrated to be mediated by the same routes as that in the endocytosis study. The ER, Golgi apparatus, and microtubules were confirmed to be important for the transport of the SLNs to both the basolateral and apical membrane sides. This study provides a more thoroughly understand of SLNs transportation crossing intestinal epithelial cell monolayers and could be beneficial for the fabrication of SLNs.

Polymer-lipid hybrid systems: merging the benefits of polymeric and lipid-based nanocarriers to improve oral drug delivery

INTRODUCTION

A number of biobarriers limit efficient oral drug absorption; both polymer-based and lipid-based nanocarriers have demonstrated properties and delivery mechanisms to overcome these biobarriers in preclinical settings. Moreover, in order to address the multifaceted oral drug delivery challenges, polymer-lipid hybrid systems are now being designed to merge the beneficial features of both polymeric and lipid-based nanocarriers.

AREAS COVERED

Recent advances in the development of polymer-lipid hybrids with a specific focus on their viability in oral delivery are reviewed. Three classes of polymer-lipid hybrids have been identified, i.e. lipid-core polymer-shell systems, polymer-core lipid-shell systems, and matrix-type polymer-lipid hybrids. We focus on their application to overcome the various biological barriers to oral drug absorption, as exemplified by selected preclinical studies.

EXPERT OPINION

Numerous studies have demonstrated the superiority of polymer-lipid hybrid systems to their non-hybrid counterparts in providing improved drug encapsulation, modulated drug release, and improved cellular uptake. These features have encouraged their applications in the delivery of chemotherapeutics, proteins, peptides, and vaccines. With further research expected to optimize the manufacturing and scaling up processes and in-depth pre-clinical pharmacological and toxicological assessments, these multifaceted drug delivery systems will have significant clinical impact on the oral delivery of pharmaceuticals and biopharmaceuticals.