Clickable Albumin Nanoparticles for Pretargeted Drug Delivery toward PD-L1 Overexpressing Tumors in Combination Immunotherapy.

We present a simple methodology to design a pretargeted drug delivery system, based on clickable anti-programmed death ligand 1 (anti-PD-L1) antibodies (Abs) and clickable bovine serum albumin (BSA) nanoparticles (NPs). Pretargeted drug delivery is based on the decoupling of a targeting moiety and a drug-delivering vector which can then react in vivo after separate injections. This may be key to achieve active targeting of drug-delivering NPs toward cancerous tissue. In pretargeted approaches, drug-delivering NPs were observed to accumulate in a higher amount in the targeted tissue due to shielding-related enhanced blood circulation and size-related enhanced tissue penetration. In this work, BSA NPs were produced using the solvent precipitation methodology that renders colloidally stable NPs, which were subsequently functionalized with a clickable moiety based on chlorosydnone (Cl-Syd). Those reactive groups are able to specifically react with dibenzocyclooctyne (DBCO) groups in a click-type fashion, reaching second-order reaction rate constants as high as 1.9 M-1·s-1, which makes this reaction highly suitable for in vivo applications. The presence of reactive Cl-Syd was demonstrated by reacting the functionalized NPs with a DBCO-modified sulfo-cyanine-5 dye. With this reaction, it was possible to infer the number of reactive moieties per NPs. Finally, and with the aim of demonstrating the suitability of this system to be used in pretargeted strategies, functionalized fluorescent NPs were used to label H358 cells with a clickable anti-PD-L1 Ab, applying the reaction between Cl-Syd and DBCO as corresponding clickable groups. The results of these experiments demonstrate the bio-orthogonality of the system to perform the reaction in vitro, in a period as short as 15 min.

"Sustained irrigation" effect enhanced the accumulation and retention of ultra-long circulating nanoparticles in tumor.

The development of ultra-long circulating nanodrug delivery systems have showed distinct advantage in maintaining the long-lasting tumor retention. Although the relationship between extended tumor retention and ultra-long plasma half-life was apparent, there was still a lack of experimental evidence to reveal the enhancement mechanism. Herein, we proposed a concept of "Sustained Irrigation" effect ("SI" effect) to elucidate that it was through sustained blood irrigation that the ultra-long circulating nanoparticles achieved long-lasting tumor retention. Besides, in order to intuitively verify the "SI" effect, we developed an "ON-OFF-ON" fluorescence switch technology. The ultra-long circulating delivery nanoparticle was constructed by encapsulating the protein with hydrophilic polymer shell. Nanoparticles with ultra-long plasma half-life (t1/2>40 h) fabricated by this method were employed as models for demonstrating the "SI" effect. The recovery of Cy5.5 fluorescence after the laser quenching meant the "fresh" Cy5.5-labeled nanoparticles were entering tumor, which confirmed the ultra-long circulating nanoparticles in blood could sustainedly irrigate to tumor. Our finding revealed the key mechanism by which ultra-long circulating NDDSs enhanced the tumor accumulation and retention, and provided experimental support for the development of ultra-long circulating delivery system in clinic.

BSA/Silver Nanoparticle-Loaded Hydrogel Film for Local Photothermal Treatment of Skin Cancer.

PURPOSE: To develop a hydrogel film containing bovine serum albumin (BSA)-coated silver nanoparticles (BSA/AgNP) and evaluate its applicability for topical photothermal treatment (PTT) of skin cancer. METHODS: BSA/AgNP-loaded hydrogel films were prepared and their swelling, bioadhesive, mechanical, and photothermal properties were characterized in vitro and in vivo. RESULTS: The synthesized BSA/AgNP exhibited a narrow size distribution with good size stability and, notably, possessed great photothermal activity that could stably maintain through repetitive laser irradiation. The BSA/AgNP-loaded hydrogel films showed favorable swelling, bioadhesive, tensile, and photothermal properties. Based on these results, when tested the anti-cancer effects in B16F10 s.c. tumor-bearing mice, the PTT with the topical treatment of BSA/AgNP-loaded hydrogel films could significantly inhibit the tumor growth by a single treatment with no apparent toxicity. CONCLUSIONS: Overall, the results of this study demonstrated that the BSA/AgNP-loaded hydrogel films may serve as an effective but safe topical PTT agent for the treatment of skin cancer.

Selenium nanoparticles inhibit the formation of atherosclerosis in apolipoprotein E deficient mice by alleviating hyperlipidemia and oxidative stress.

Atherosclerosis can cause severe cardiovascular diseases, which is the most common cause of death in the world. It's of great significance to study the prevention and treatment of atherosclerosis. Selenium nanoparticles (SeNPs) has drawn more and more attention due to high biological activity, high bioavailability, strong antioxidant capacity and low toxicity, exhibiting great potential in biomedical application. Thus, this study aimed at explore the anti-atherosclerotic effect of two kinds of SeNPs, bovine serum albumin (BSA) surface-decorated SeNPs and chitosan (CS) surface-decorated SeNPs (CS-SeNPs), in apolipoprotein E deficient (ApoE-/-) mice fed with a high-cholesterol and high-fat diet, and the possible mechanisms. The results demonstrated that both BSA-SeNPs (25, 50 and 100 µg Se/kg body weight/day) and CS-SeNPs (50 µg Se/kg body weight/day) could reduce atherosclerotic lesions in ApoE-/- mice after oral administration for 12 weeks. And these effects might mainly attributed to the ability of BSA-SeNPs and CS-SeNPs to inhibit hyperlipidemia by suppressing hepatic cholesterol and fatty acid metabolism, and alleviate oxidative stress by enhancing antioxidant activity. Moreover, the benefits of BSA-SeNPs were dose-dependent and the medium dose of BSA-SeNPs (50 µg Se/kg body weight/day) was optimal. Generally, BSA-SeNPs with mean size 38.5 nm and negative surface charge showed better anti-atherosclerotic effect than CS-SeNPs with mean size 65.8 nm and positive surface charge. These results suggested that SeNPs could significantly alleviate the formation of atherosclerosis in ApoE-/- mice, possibly by inhibiting hyperlipidemia and oxidative stress, exhibiting a potential to serve as an anti-atherosclerotic agent.

Delivery of functional exogenous proteins by plant-derived vesicles to human cells in vitro.

Plant-derived extracellular vesicles (EVs) gain more and more attention as promising carriers of exogenous bioactive molecules to the human cells. Derived from various edible sources, these EVs are remarkably biocompatible, biodegradable and highly abundant from plants. In this work, EVs from grapefruit juice were isolated by differential centrifugation followed by characterization of their size, quantity and morphology by nanoparticle tracking analysis, dynamic light scattering, atomic force microscopy and cryo-electron microscopy (Cryo-EM). In Cryo-EM experiments, we visualized grapefruit EVs with the average size of 41 ± 13 nm, confirmed their round-shaped morphology and estimated the thickness of their lipid bilayer as 5.3 ± 0.8 nm. Further, using cell culture models, we have successfully demonstrated that native grapefruit-derived extracellular vesicles (GF-EVs) are highly efficient carriers for the delivery of the exogenous Alexa Fluor 647 labeled bovine serum albumin (BSA) and heat shock protein 70 (HSP70) into both human peripheral blood mononuclear cells and colon cancer cells. Interestingly, loading to plant EVs significantly ameliorated the uptake of exogenous proteins by human cells compared to the same proteins without EVs. Most importantly, we have confirmed the functional activity of human recombinant HSP70 in the colon cancer cell culture upon delivery by GF-EVs. Analysis of the biodistribution of GF-EVs loaded with 125I-labeled BSA in mice demonstrated a significant uptake of the grapefruit-derived extracellular vesicles by the majority of organs. The results of our study indicate that native plant EVs might be safe and effective carriers of exogenous proteins into human cells.

An Albumin-Based Therapeutic Nanosystem for Photosensitizer/Protein Co-Delivery to Realize Synergistic Cancer Therapy.

Oxygen-dependent photodynamic therapy (PDT) is hindered by the limited availability of endogenous oxygen in solid tumors and low tumor accumulation of photosensitizers. Herein, we developed a biocompatible cancer-targeted therapeutic nanosystem based on cRGD conjugated bovine serum albumin (CBSA) co-loaded with a photosensitizer (chlorin e6, Ce6) and a therapeutic protein (cytochrome c, Cytc) for synergistic photodynamic and protein therapy. The nanosystem (Ce6/Cytc@CBSA) can target αVß3 integrin overexpressed cancer cells to improve tumor accumulation due to incorporation of cRGD. In the intracellular environment, Ce6 is released to produce toxic singlet oxygen upon near-infrared irradiation. At the same time, the therapeutic protein, Cytc, can induce programmed cell death by activating the downstream caspase pathway. Most importantly, Cytc with the catalase-like activity accelerates O2 generation by decomposing excess H2O2 in cancer cells, thereby relieving the PDT-induced hypoxia to enhance therapeutic efficacy. Both in vitro and in vivo studies reveal the significantly improved antitumor effects of the combined photodynamic/protein therapy, indicating that Ce6/Cytc@CBSA shows great potential in synergetic cancer treatments.

Protamine and BSA-dextran complex emulsion improves oral bioavailability and anti-tumor efficacy of paclitaxel.

Food protein and polysaccharide complex emulsions are safe carriers of hydrophobic drugs and nutrients. To improve oral bioavailability and therapeutic/healthy efficacy of hydrophobic drugs and nutrients, herein, protamine (PRO), a cationic cell-penetrating peptide, was introduced into protein and polysaccharide complex emulsion. The electrostatic complex of PRO and BSA-dextran conjugate (BD) produced by Maillard reaction was used as emulsifier to produce oil-in-water emulsion (@BD/PRO). The BSA molecules were crosslinked at the oil-water interface by a heat treatment and the PRO chains were simultaneously anchored in the interface. BD emulsion (@BD) without PRO was produced for comparation. Paclitaxel (PTX), a hydrophobic antineoplastic drug, was encapsulated in the emulsions with 99% loading efficiency and 6.4% loading capacity. The emulsions had long-term stability. The bioavailability and H22 tumor inhibition efficacy of PTX@BD/PRO were 40% and 70% higher than those of PTX@BD, respectively, after oral administration in the mice. More importantly, orally administrated PTX@BD/PRO had the same anti-tumor efficacy as intravenously injected commercial PTX injection. No abnormality was observed in the main organs of the mice after consecutive oral administration of PTX@BD/PRO. This study indicates that @BD/PRO is an excellent carrier of hydrophobic drugs/nutrients and is suitable for long-term oral administration.

Targeted MRI and chemotherapy of ovarian cancer with clinic available nano-drug based nanoprobe.

Cancer is the leading cause of death worldwide, and chemotherapy, as its main treatment, has side effects in clinical application due to lack of targeting selectivity to tumor tissues. Theranostic nanomaterials have shown wonderful functions for the diagnosis and therapy of disease benefitting from the controllability of nanomaterials. However, there is still little available for clinical transformation due to the uncertain biocompatibility. It is urgent to develop nanoprobes possessing bright transformation potentials. This study reports a facile biomineralization route to synthesize the theranostic nanoprobe using the clinic available nano-drug (trademark Abraxane). Further profiting from the binding ability of albumin to metal cations, we successfully prepared biocompatible nanoprobe, BSA-Gd2O3/PTX@Anti-HE4 mAb, for the targeted magnetic resonance imaging and chemotherapy of ovarian carcinoma. The obtained nanoprobe has the advantages of uniform particle size, good dispersibility and favorable stability. In vivo and in vitro experiment results showed that the nanoprobe can realize targeted magnetic resonance imaging and chemotherapy of ovarian carcinoma. Such a novel multifunctional nanoprobe based on clinic nano-drug might be promising for clinic transformation.

Preparation and Evaluation of Cabazitaxel-Loaded Bovine Serum Albumin Nanoparticles for Prostate Cancer.

PURPOSE: Cabazitaxel (CBZ) is a new taxane-based antitumor drug approved by the FDA for the treatment of prostate cancer, especially for patients with advanced prostate cancer for whom docetaxel is ineffective or causes aggravation. However, Tween 80 injection can cause serious allergic reactions, and CBZ itself has strong toxicity, adverse reactions, and poor tumor selectivity, which greatly limits its clinical applications. Therefore, the CBZ-loaded bovine serum albumin nanoparticles (CBZ-BSA-Gd-NPs) were developed to overcome the allergenic response of Tween 80 and realize the integration of diagnosis and treatment. METHODS: CBZ-BSA-Gd-NPs were prepared by the biomineralization method. The characterization, magnetic resonance imaging (MRI), safety, and antitumor activity of the nanoparticles were evaluated in vitro and in vivo. RESULTS: The prepared nanoparticles were uniform in size (166 nm), with good MRI performance and stability over 24 h. Compared with CBZ-Tween 80 injection, CBZ-BSA-Gd-NPs showed much lower hemolysis, similar tumor inhibition, and enhanced cellular uptake in vitro. The pharmacokinetic behavior of CBZ-BSA-Gd-NPs in rats showed that the retention time of the nanoparticles was prolonged, the clearance rate decreased, and the area under the drug-time curve increased. The distribution of CBZ-BSA-Gd-NPs in nude mice was characterized by UPLC-MS/MS and MRI, and the results showed that CBZ-BSA-Gd-NPs could effectively target tumor tissues with reduced distribution in the heart, liver, spleen, lungs, and kidneys compared with CBZ-Tween 80, which indicated that CBZ-BSA-Gd-NPs not only had a passive targeting effect on tumor tissue but also achieved the integration of diagnosis and treatment. In vivo, CBZ-BSA-Gd-NPs showed improved tumor inhibitory effect with a safer profile. CONCLUSION: In summary, CBZ-BSA-Gd-NPs can serve as an effective therapeutic drug carrier to deliver CBZ into prostate cancer, and realize the integration of diagnosis and therapy.

Effective Chemotherapy of Lung Cancer Using Bovine Serum Albumin-Coated Hydroxyapatite Nanoparticles.

BACKGROUND Successful chemotherapy of lung cancer relies largely on the use of a good drug delivery system (DDS). We successfully constructed a hybrid DDS comprised of hydroxyapatite (HAP) nanoparticles and bovine serum albumin (BSA). MATERIAL AND METHODS The HAP nanoparticles were selected as the core to encapsulate the anticancer drug doxorubicin (DOX), followed by surface modification of BSA as a stabilizer and shielding corona to finally prepare the hybrid DDS (BSA/HAP/DOX). RESULTS The following characterizations revealed that BSA/HAP nanoparticles have high stability, high biocompatibility, and good DOX-loading capability to meet in vivo applications. Moreover, BSA/HAP/DOX can enhance the cellular uptake of drug in A549 cells (lung cancer cells). Most importantly, BSA/HAP had better in vivo tumor targetability than bare HAP nanoparticles, which resulted in stronger anticancer efficacy both in vitro and in vivo than free DOX or HAP/DOX, and greatly decreased the adverse effects of free DOX. CONCLUSIONS Our hybrid DDS shows potential to be applied in more advanced application of cancer therapy.

Tumor pH-responsive metastable-phase manganese sulfide nanotheranostics for traceable hydrogen sulfide gas therapy primed chemodynamic therapy.

Manganese-based nanomaterials have piqued great interest in cancer nanotheranostics, owing to their excellent physicochemical properties. Here we report a facile wet-chemical synthesis of size-controllable, biodegradable, and metastable γ-phase manganese sulfide nanotheranostics, which is employed for tumor pH-responsive traceable gas therapy primed chemodynamic therapy (CDT), using bovine serum albumin (BSA) as a biological template (The final product was denoted as MnS@BSA). The as-prepared MnS@BSA can be degraded in response to the mildly acidic tumor microenvironment, releasing hydrogen sulfide (H2S) for gas therapy and manganese ions for magnetic resonance imaging (MRI) and CDT. In vitro experiments validated the pH-responsiveness of MnS@BSA at pH 6.8 and both H2S gas and •OH radicals were detected during its degradation. In vivo experiments showed efficiently tumor turn-on T1-weighted MRI, significantly suppressed tumor growth and greatly prolonged survival of tumor-bearing mice following intravenous administration of MnS@BSA. Our findings indicated that MnS@BSA nanotheranostics hold great potential for traceable H2S gas therapy primed CDT of cancer.

Preparation and in vitro release profiling of PLGA microspheres containing BSA as a model protein

Conventional drug formulations are incapable of adequate delivery of proteins and peptides for therapeutic purposes. As these molecules have very short biological half-life, multiple dosing is required to achieve the desirable therapeutic effects. Microspheres are able to encapsulate proteins and peptide in the polymeric matrix while protecting them from enzymatic degradation. In this study Bovine Serum Albumin (BSA) matrix type microspheres were fabricated using Polylactide-co-glycolide (PLGA) by double emulsion solvent evaporation method. The effects of variables such as homogenizer speed, molecular weight of polymer and the effect of pH of the water phases, were investigated against factors such as drug loading, encapsulation efficiency, morphology, size, drug distribution and release profile of the microspheres. Results, suggested that an increase in homogenization speed leads to a decrease in microsphere size. The increase in homogenization speed also caused a significant effect on the release profile only when higher molecular weight of polymer had been used.. The pH change of the internal aqueous phase led to modification of surface morphology of spheres to a porous structure that significantly increased the total amount of released protein. Integrity of protein structure was intact as shown by SDS-PAGE. According to the results, it can be concluded that we achieved a reproducible method regarding controlled protein delivery for different sizes of particles.

E-Selectin-Binding Peptide-Modified Bovine Serum Albumin Nanoparticles for the Treatment of Acute Lung Injury.

Currently, there is no specific treatment for acute lung injury (ALI). E-selectin-binding peptide (Esbp), a high-affinity peptide that delivers drugs targeting inflammatory vascular endothelial cells, can bind to E-selectin and act as a targeting ligand for selective drug delivery. In this study, we coupled the thiol groups of Esbp to the amino groups on the surface of bovine serum albumin (BSA) using succinimidyl iodoacetic acid to make Esbp-modified BSA nanoparticles (BSANPs) at the average ratio of 19.3 µg Esbp to 1 mg BSA. The Esbp-modified BSANPs were spherical in shape and had a particle size of 266.7 ± 2.7 nm, polydispersity index of 0.165 ± 0.02, zeta potential of - 33.64 ± 1.23 mV, encapsulation efficiency of 84.3 ± 2.3%, and drug loading of 6.7 ± 0.32%. The cumulative release rate of dexamethasone-loaded Esbp-modified BSANPs was 51.2% within 12 h, significantly lower than that of 88.2% of free drugs. Moreover, Esbp-modified BSANPs could be uptaken in vitro by activated human umbilical vein endothelial cells and in vivo by the lungs of the established ALI mouse model. These results indicated that our Esbp-modified BSANPs delivery system has characteristics of good targeting ability and biocompatibility and is able to inhibit inflammation. Overall, our Esbp-modified BSANPs delivery system has therapeutic potentials as a new targeting drug system for the treatment of ALI in the future.

Hydrogel microspheres evading alveolar macrophages for sustained pulmonary protein delivery.

Pulmonary delivery is a highly attractive alternative to injections for biologics such as therapeutic proteins. However, bioavailabilities generally suffer from the presence of phagocytic cells that clear particulate matter entering the lung. In this study, microgel particles were developed using an all-aqueous two-phase system approach and evaluated for their efficacy as an inhalable controlled release system. Norbornene- and thiol-modified four- and eight-armed poly (ethylene glycol) with an average molecular mass of 10,000 Da were prepared as macromonomers for microgel formation. Emulsions of precursor solution droplets containing macromonomers and Irgacure 2959 as photocatalyst were prepared in a dextran solution. Irradiation with UV light was used to covalently crosslink the droplets by triggering the thiol-ene reaction. The resulting microgels were processed to dry powder inhaler formulations, and respirable aerodynamic sizes were assessed in vitro. Microgels were loaded with the model proteins lysozyme and bovine serum albumin, with encapsulation efficiencies of 51.5% and 73.6%, respectively. Depending on the macromonomer type, protein-loaded microgels released their cargo over a 6-14 day period. In an MTT assay, the particles did not show significant cytotoxicity, and their recognition by alveolar macrophages was considerably lower than for polystyrene control particles. This makes the microgels a promising pulmonary delivery system for proteins and other biologics.

Imine bond formation: A novel concept to incorporate peptide drugs in self-emulsifying drug delivery systems (SEDDS).

HYPOTHESIS: Because of its hydrophilic character the peptide drug Polymyxin B (PMB) cannot be incorporated in lipophilic nanocarrier systems such as self-emulsifying drug delivery systems (SEDDS) for oral administration. Due to the formation of imine conjugates between the primary amino groups of PMB and the carbonyl group of cinnamaldehyde, however, drug lipophilicity might be sufficiently raised for incorporation in SEDDS. METHODS: Imine bonds were formed between the primary amino groups of PMB and the carbonyl group of cinnamaldehyde. PMB-cinnamaldehyde conjugate was characterized regarding degree of substitution, log P and release of PMB due to interaction with bovine serum albumin (BSA), SEDDS loading and cell viability. RESULTS: 87.1% of primary amines formed imines with cinnamaldehyde. Log P was increased 69.183 - folds. BSA triggered release of PMB was 45.2%, 64.9% and 80.6% within 16 h. Log DSEDDS/Release medium of PMB-cinnamaldehyde conjugate was 3.4. CONCLUSION: According to these findings, the concept of imine bond formation with cinnamaldehyde can be considered as a novel concept for increasing lipophilicity of the hydrophilic antibiotic peptide PMB.

A novel theranostic system of AS1411 aptamer-functionalized albumin nanoparticles loaded on iron oxide and gold nanoparticles for doxorubicin delivery.

Recently DNA aptamers have attracted remarkable attention as possible targeting ligands since selective targeting of cancer cells is a critical step in cancer diagnosis and therapy. Here, the development of AS1411 aptamer-functionalized albumin nanoparticles loaded on iron oxide and gold nanoparticles is reported for target delivery of the well-known anticancer drug of doxorubicin (Dox). Iron oxide nanoparticles (IONPs) and gold nanoparticles (GNPs) were prepared by ultrasound-assisted and controlled seeded growth synthetic methods, respectively. The nanocarrier was synthesized by a desolvation cross-linking method and characterized by dynamic light scattering, zeta potential measurement, thermogravimetric analysis, transmission electron microscopy, as well as vibrating sample magnetometer. The synthesized nanoparticles were found to be spherical with an average diameter of 120 nm and zeta potential of about -50.3 mV. The in-vitro anti-tumor effect of the designed delivery vehicle on MCF7 and SKBR3 human cancer cells was evaluated by MTT assay. The experimental results revealed that it could significantly inhibit the proliferation of cancerous cells. Moreover, GNPs and IONPs with the coating of albumin did not show any toxicity. AS1411 aptamer-functionalized nanoparticles improved cellular uptake and efficiency to MCF7 breast cancer cells as compared to non-targeting nanoparticles because of the high affinity of mentioned aptamer toward the overexpressed nucleolin on MCF7 cell surface.

Gold nanocluster-loaded hybrid albumin nanoparticles with fluorescence-based optical visualization and photothermal conversion for tumor detection/ablation.

Gold nanoclusters (AuNCs) are viewed as effective hyperthermal agents for the treatment of tumors. Whereas AuNCs formed by the agglomeration of several to tens of gold atoms (<1-2 nm) possess significant fluorescence, they have a negligible hyperthermal effect, while AuNCs comprised of spherical gold nanoparticles (AuNPs > a few nanometers) have a marked hyperthermic effect but lose their inherent fluorescence and obstruct the intensity of neighboring fluorescent dyes due to Forster resonance energy transfer (FRET). To achieve both hyperthermia and fluorescence-based optical visualization, we generated hybrid albumin nanoparticles containing AuNCs (~88 nm) comprising AuNPs (~4.5 nm). We generated a series of formulated AuNCs and optimized the size, morphology, NIR absorbance (600-900 nm), hyperthermal activity, and fluorescence spectral characters of the resulting hybrid albumin nanoparticles (AuNCs/BSA-NPs) by considering the interparticle distance between the AuNPs and Cy5.5. Among these, AuNCs/BSA-NPs (formula D) had a strong hyperthermic effect and had well-preserved fluorescence intensity (from the attached Cy5.5) due to localized surface plasmon resonance (LSPR) and a reduction in FRET. These AuNCs/BSA-NPs were able to elevate the surface tumor temperature of HCT116-bearing mice to >50 °C following 808 nm laser irradiation (1.5 W/cm2, 10 min), which remarkably suppressed tumor growth (17.8 ±â€¯16.9 mm3vs. PBS and AuNCs/BSA-NPs (formula E): ~1850 and ~1250 mm3, respectively). Also, Cy5.5-modified AuNCs/BSA-NPs (formula D) showed good performance in optical fluorescence imaging of target tumors in HCT116 tumor-bearing mice. Together, our results indicate that the interparticle distance between albumin or Cy5.5 and AuNPs/AuNCs can be optimized to achieve both hyperthermia and fluorescence emission by striking a balance between LSPR and FRET effects. We believe that the AuNC/BSA-NPs formulation presented here can serve as a potential platform for both optically visualizing and treating colon cancers.

Binding Characterization of Aptamer-Drug Layered Microformulations and In Vitro Release Assessment.

Efficient delivery of adequate active ingredients to targeted malignant cells is critical, attributing to recurrent biophysical and biochemical challenges associated with conventional pharmaceutical delivery systems. These challenges include drug leakage, low targeting capability, high systemic cytotoxicity, and poor pharmacokinetics and pharmacodynamics. Targeted delivery system is a promising development to deliver sufficient amounts of drug molecules to target cells in a controlled release pattern mode. Aptameric ligands possess unique affinity targeting capabilities which can be exploited in the design of high pay-load drug formulations to navigate active molecules to the malignant sites. This study focuses on the development of a copolymeric and multifunctional drug-loaded aptamer-conjugated poly(lactide-co-glycolic acid)-polyethylenimine (PLGA-PEI) (DPAP) delivery system, via a layer-by-layer synthesis method, using a water-in-oil-in-water double emulsion approach. The binding characteristics, targeting capability, biophysical properties, encapsulation efficiency, and drug release profile of the DPAP system were investigated under varying conditions of ionic strength, polymer composition and molecular weight (MW), and degree of PEGylation of the synthetic core. Experimental results showed increased drug release rate with increasing buffer ionic strength. DPAP particulate system obtained the highest drug release of 50% at day 9 at 1 M NaCl ionic strength. DPAP formulation, using PLGA 65:35 and PEI MW of ∼800 Da, demonstrated an encapsulation efficiency of 78.93%, and a loading capacity of 0.1605 mg bovine serum albumin per mg PLGA. DPAP (PLGA 65:35, PEI MW∼25 kDa) formulation showed a high release rate with a biphasic release profile. Experimental data depicted a lower targeting power and reduced drug release rate for the PEGylated DPAP formulations. The outcomes from the present study lay the foundation to optimize the performance of DPAP system as an effective synthetic drug carrier for targeted delivery.

Hepatic and Intrahepatic Targeting of Hydrogen Sulfide Prodrug by Bioconjugation.

Hydrogen sulfide (H2S) is an endogenous gaseous transmitter known to play an important role in biological functions. For the hepatic and intrahepatic targeting of H2S prodrug at the cellular level, we developed two types of sulfo-albumins, in which five sulfide groups (source of H2S) were covalently bound to succinylated (Suc) or galactosylated (Gal) bovine serum albumin (BSA). Sulfo-BSA-Suc and polyethylene glycol (PEG)-Sulfo-BSA-Gal, both released H2S in the 5 mM glutathione solution, but not in the plasma. Sulfo-BSA-Suc and PEG-Sulfo-BSA-Gal were taken up by RAW264.7 cells (mouse macrophage-like cells) and Hep G2 cells (human hepatocellular carcinoma cells), respectively, and H2S was released. These results indicate that Sulfo-BSA-Suc and PEG -Sulfo-BSA-Gal selectively released H2S intracellularly. In a biodistribution study, up to 80% of 111In-labeled Sulfo-BSA-Suc and PEG-Sulfo-BSA-Gal rapidly accumulated in the liver, 30 min after intravenous injection in mice. Furthermore, 111In-labeled Sulfo-BSA-Suc and PEG-Sulfo-BSA-Gal predominantly accumulated in liver nonparenchymal (endothelial cells and Kupffer cells) and parenchymal cells (hepatocytes), respectively. These findings suggest that targeted delivery of H2S prodrug to a specific type of liver cells was successfully achieved by bioconjugation.

Improved drug targeting to liver tumor by sorafenib-loaded folate-decorated bovine serum albumin nanoparticles.

BACKGROUND: To prepare sorafenib-loaded folate-decorated bovine serum nanoparticles (FA-SRF-BSANPs) and investigate their effect on the tumor targeting. METHODS: The nanoparticles were characterized and evaluated by in vivo and in vitro experiments. RESULTS: SRF-loaded BSA nanoparticles (SRF-BSANPs) was first prepared and modified with folic acid by chemical coupling to obtain FA-SRF-BSANPs. The average particle size, zeta potential, entrapment efficiency, and drug loading of the optimized FA-SRF-BSANPs were 158.00 nm, -16.27 mV, 77.25%, and 7.73%, respectively. The stability test showed that FA-SRF-BSANPs remained stable for more than 1 month at room temperature. The TEM analysis showed that the surface of FA-SRF-BSANPs was nearly spherical. XRD analysis showed that the drug existed in. the nanoparticles in an amorphous state. FA-SRF-BSANPs can promote the intracellular uptake of hepatoma cells (SMMC-7721) with the strongest inhibitory effect compared with SRF-BSANPs and sorafenib solution. Furthermore, the tumor targeting of FA-SRF-BSANPs (Ctumor/Cblood, 0.666 ± 0.053) was significantly higher than those of SRF-BSANPs (Ctumor/Cblood, 0.560 ± 0.083) and sorafenib-solution (Ctumor/Cblood, 0.410 ± 0.038) in nude mice with liver cancer. CONCLUSION: FA-modified albumin nanoparticles are good carriers for delivering SRF to the tumor tissue, which can improve the therapeutic effect and reduce the side effects of the drug.