Surface Modification of Cisplatin-Complexed Gold Nanoparticles and Its Influence on Colloidal Stability, Drug Loading, and Drug Release

Review of Gold Nanoparticles: Synthesis, Properties, Shapes, Cellular Uptake, Targeting, Release Mechanisms and Applications in Drug Delivery and Therapy

The remarkable versatility of gold nanoparticles (AuNPs) makes them innovative agents across various fields, including drug delivery, biosensing, catalysis, bioimaging, and vaccine development. This paper provides a detailed review of the important role of AuNPs in drug delivery and therapeutics. We begin by exploring traditional drug delivery systems (DDS), highlighting the role of nanoparticles in revolutionizing drug delivery techniques. We then describe the unique and intriguing properties of AuNPs that make them exceptional for drug delivery. Their shapes, functionalization, drug-loading bonds, targeting mechanisms, release mechanisms, therapeutic effects, and cellular uptake methods are discussed, along with relevant examples from the literature. Lastly, we present the drug delivery applications of AuNPs across various medical domains, including cancer, cardiovascular diseases, ocular diseases, and diabetes, with a focus on in vitro and in vivo cancer research.

Antimicrobial assay and controlled drug release studies with novel eugenol imprinted p(HEMA)-bacterial cellulose nanocomposite, designed for biomedical applications

In this study, a novel bio-composite material that allow sustained release of plant derived antimicrobial compound was developed for the biomedical applications to prevent the infections caused by microorganisms resistant to commercial antimicrobials agents. With this aim, bacterial cellulose (BC)-p(HEMA) nanocomposite film that imprinted with eugenol (EU) via metal chelated monomer, MAH was prepared. Firstly, characterization studies were utilized by FTIR, SEM and BET analysis. Then antimicrobial assays, drug release studies and in vitro cytotoxicity test were performed. A significant antimicrobial effect against both Gram (+) Staphylococcus aureus and Gram (-) Escherichia coli bacteria and a yeast Candida albicans were observed even in low exposure time periods. When antimicrobial effect of EU compared with commercially used agents, both antifungal and antibacterial activity of EU were found to be higher. Then, sustained drug release studies showed that approximately 55% of EU was released up to 50 h. This result proved the achievement of the molecular imprinting for an immobilization of molecules that desired to release on an area in a long-time interval. Finally, the in vitro cytotoxicity experiment performed with the mouse L929 cell line determined that the synthesized EU-imprinted BC nanocomposite was biocompatible.

Preadsorbed Chymotrypsin Modulated the Composition of Protein Corona and Immunological Response

It is well-known that proteins after administration into biological environments adsorb on the surface of nanoparticles (NPs). The biological identity could be determined by protein corona, but whether and how the preadsorbed molecules impact the composition of the corona and immunological response have rarely been reported. Here, the effects of preadsorbed chymotrypsin (Chy) on forming protein corona and subsequent immunological response are reported. We find that preadsorbed Chy on the surface of AuNPs results in a protein corona with enriched immunoglobulins and reduced human serum albumin protein, which further affect the polarization of macrophages into specific phenotypes. Our study suggests that the protein surrounding the nanoparticles could affect the protein corona and immunological response, which may direct the preparation of multifunctional nanomedicine for future studies.

Nitric oxide releasing novel amino acid-derived polymeric nanotherapeutic with anti-inflammatory properties for rapid wound tissue regeneration

Endogenous gasotransmitter nitric oxide (NO) is a central signalling molecule that modulates wound healing by maintaining homeostasis, collagen formation, wound contraction, anti-microbial action and accelerating tissue regeneration. The optimum delivery of NO using nanoparticles (NPs) is clinically challenging; hence, it is drawing significant attention in wound healing. Herein, a novel polymeric nanoplatform loaded with sodium nitroprusside (SP) NPs was prepared and used for wound healing to obtain the sustained release of NO in therapeutic quantities. SP NPs-induced excellent proliferation (∼300%) of mouse fibroblast (L929) cells was observed. With an increase in the SP NPs dose at 200 μg mL-1 concentration, a 200% upsurge in proliferation was observed along with enhanced migration, and only 17.09 h were required to fill the 50% gap compared to 37.85 h required by the control group. Further, SP NPs showed an insignificant impact on the coagulation cascade, revealing safe wound-healing treatment when tested in isolated rat RBCs. Additionally, SP NPs exhibited excellent angiogenic activity at a 10 μg mL-1 dose. Moreover, the formulated SP nanoformulation is non-irritant, non-toxic, and does not produce any skin sensitivity reaction on the rat's skin. Further, an in vivo wound healing study revealed that within 11 days of treatment with SP nanoformulation, 99.2 ± 1.0% of the wound was closed, while in the control group, only 45.5 ± 3.8% was repaired. These results indicate that owing to sustained NO release, the SP NP and SP nanoformulations are paramount with enormous clinical potential for the regeneration of wound tissues.

Stability-Enhanced Cisplatin Gold Nanoparticles As Therapeutic Anticancer Agents

Using dendron chemistry, we developed stability enhanced, carboxylate surface modified (negatively charged dendron) AuNPs (Au-NCD). Since the carboxylate surface of Au-NCD is optimal for complexation with cisplatin (Pt) moieties, we further synthesized Pt loaded Au-NCD (Au-NCD/Pt) to serve as potential therapeutic anticancer agents. The size distribution, zeta potential and surface plasmon resonance of both Au-NCDs and Au-NCD/Pt were characterized via dynamic light scattering, scanning transmission electron microscopy and ultraviolet-visible spectrophotometry. Surface chemistry, Pt uptake, and Pt release were evaluated using inductively coupled plasma-mass spectrometry and X-ray photoelectron spectroscopy. Colloidal stability in physiological media over a wide pH range (1 to 13) and shelf-life stability (up to 6 months) were also assessed. Finally, the cytotoxicity of both Au-NCD and Au-NCD/Pt to Chinese hamster ovary cells (CHO K1; as a normal cell line) and to human lung epithelial cells (A549; as a cancer cell line) were evaluated. The results of these physicochemical and functional cytotoxicity studies with Au-NCD/Pt demonstrated that the particles exhibited superlative colloidal stability, cisplatin uptake and in vitro anticancer activity despite low amounts of Pt release from the conjugate.

Gold Nanorods with Mesoporous Silica Shell: A Promising Platform for Cisplatin Delivery

The versatile combination of metal nanoparticles with chemotherapy agents makes designing multifunctional drug delivery systems attractive. In this work, we reported cisplatin's encapsulation and release profile using a mesoporous silica-coated gold nanorods system. Gold nanorods were synthesized by an acidic seed-mediated method in the presence of cetyltrimethylammonium bromide surfactant, and the silica-coated state was obtained by modified Stöber method. The silica shell was modified first with 3-aminopropyltriethoxysilane and then with succinic anhydride to obtain carboxylates groups to improve cisplatin encapsulation. Gold nanorods with an aspect ratio of 3.2 and silica shell thickness of 14.74 nm were obtained, and infrared spectroscopy and ζ potential studies corroborated surface modification with carboxylates groups. On the other hand, cisplatin was encapsulated under optimal conditions with an efficiency of ~58%, and it was released in a controlled manner over 96 h. Furthermore, acidic pH promoted a faster release of 72% cisplatin encapsulated compared to 51% in neutral pH.

Cancer Treatment Using Different Shapes of Gold-Based Nanomaterials in Combination with Conventional Physical Techniques

The conventional methods of cancer treatment and diagnosis, such as radiotherapy, chemotherapy, and computed tomography, have developed a great deal. However, the effectiveness of such methods is limited to the possible failure or collateral effects on the patients. In recent years, nanoscale materials have been studied in the field of medical physics to develop increasingly efficient methods to treat diseases. Gold nanoparticles (AuNPs), thanks to their unique physicochemical and optical properties, were introduced to medicine to promote highly effective treatments. Several studies have confirmed the advantages of AuNPs such as their biocompatibility and the possibility to tune their shapes and sizes or modify their surfaces using different chemical compounds. In this review, the main properties of AuNPs are analyzed, with particular focus on star-shaped AuNPs. In addition, the main methods of tumor treatment and diagnosis involving AuNPs are reviewed.

Drawbacks in the efficient monitoring of gold nanoparticle-based cisplatin delivery systems formation by HPLC-ICP-MS

Since chemotherapy suffers many limitations related to side effects of anticancer drugs (e.g. cisplatin - CDDP), nanoparticles are probed as carriers in targeted drug delivery. Gold nanoparticles (AuNPs) are broadly investigated due to their biocompatibility, nontoxicity, and tunable surface. Despite many AuNPs-cisplatin systems (AuNP-CS) reports found in the literature, only a few include studies of their synthesis and formation efficiency using analytical tools providing simultaneously qualitative and quantitative analytical information. Therefore, this research continues our previous study of AuNP-CS formation investigated by capillary electrophoresis with inductively coupled plasma mass spectrometry (ICP-MS). Namely, it presents the analogical approach but employs the coupling of another separation technique: isocratic reversed-phase high-performance liquid chromatography. The study concerns the difficulties of analytical method optimization path and contains a discussion of the observed problematic issues related to the analysis and preparation of AuNP-CS. Moreover, the presented work confronts the performance and applicability of both tools for the scrutiny of AuNP-CS, especially considering the comparison of their resolution power.

Image-Guided Nanodelivery of Pt(IV) Prodrugs to GRP-Receptor Positive Tumors

Over the last decades, gold nanoparticles (AuNPs) have proven to be remarkable tools for drug delivery and theranostic applications in cancer treatment. On the other hand, Pt(IV) prodrugs have been employed as an interesting alternative to the more common Pt(II) complexes, such as cisplatin, for cancer chemotherapy. Searching to design an image-guided nanocarrier to deliver selectively Pt(IV) prodrugs to tumors expressing the gastrin releasing peptide receptor (GRPR), we have synthesized small core AuNPs carrying a thiolated DOTA derivative, a GRPR-targeting bombesin analog (BBN[7-14]) and a Pt(IV) prodrug attached to the AuNPs without (AuNP-BBN-Pt1) or with a PEGylated linker (AuNP-BBN-Pt2 and AuNP-BBN-Pt3). In the GRPR+ prostate cancer PC3 cell line, the cytotoxic activity of the designed AuNP-BBN-Pt nanoparticles is strongly influenced by the presence of the PEGylated linker. Thus, AuNP-BBN-Pt1 displayed the lowest IC₅₀ value (9.3 ± 2.3 µM of Pt), which is comparable to that exhibited by cisplatin in the same cell line. In contrast, AuNP-BBN-Pt1 showed an IC₅₀ value of 97 ± 18 µM of Pt in the non-tumoral RWPE-1 prostate cells with a much higher selective index (SI) towards PC3 cells (SI = 10) when compared with cisplatin (SI = 1.3). The AuNPs were also successfully labeled with ⁶⁷Ga and the resulting ⁶⁷Ga-AuNP-BBN-Pt were used to assess their cellular uptake in PC3 cells, with AuNP-BBN-Pt1 also displaying the highest cellular internalization. Finally, intratumoral administration of ⁶⁷Ga-AuNP-BBN-Pt1 in a PC3 tumor-bearing mice showed a prolonged retention of the nanoparticle compared to that of cisplatin, with optimal in vivo stability and 20% of the injected platinum remaining in the tumor after 72 h post-injection. Furthermore, microSPECT imaging studies confirmed the uptake and considerable retention of the ⁶⁷Ga-labeled AuNPs in the tumors. Overall, these results show the potential of these targeted AuNPs loaded with Pt(IV) prodrugs for prostate cancer theranostics.

Bio-Inspired Surface Modification of Magnetite Nanoparticles with Dopamine Conjugates

Organically-coated nanomaterials are intensively studied and find numerous applications in a wide range of areas from optics to biomedicine. One of the recent trends in material science is the application of bio-mimetic polydopamine coatings that can be produced on a variety of substrates in a cost-efficient way under mild conditions. Such coatings not only modify the biocompatibility of the material but also add functional amino groups to the surface that can be further modified by classic conjugation techniques. Here we show an alternative strategy for substrates modification using dopamine conjugates instead of native dopamine. Compared to the classic scheme, the proposed strategy allows separation of the “organic” and “colloidal” stages, and simplified identification and purification steps. Modification with pre-modified dopamine made it possible to achieve high loading capacities with active components up to 10.5% wt. A series of organo-inorganic hybrids were synthesized and their bioactivity was analyzed.

Mushroom-brush transitional conformation of mucus-inert PEG coating improves co-delivery of oral liposome for intestinal metaplasia therapy

The blocking of gastric mucosal intestinal metaplasia (IM) has been considered to be the pivotal method to control the occurrence of gastric cancer. However, there is still a lack of effective therapeutic agent. Here, we developed mucus-penetrating liposome system by covering surface with polyethylene glycol (PEG) chains (hydrophilic and electroneutral mucus-inert material) to co-delivery candidate drugs combination. Then studied the impact on the transmucus performance of different conformations, which were constructed by controlling the density of PEG chains on the surface. The results showed that the particle size of 5%PEG-Lip was less than 120 nm, the polydispersity index was less than 0.3, and the surface potential tended to be neutral. The D value (long chain spacing) of 5% PEG-Lip was 3.25 nm, which was close to the R_F value (diameter of spherical PEG long chain group without external force interference) of 3.44 nm, and the L value (extended length) was slightly larger than 3.44 nm. In this case, PEG showed mushroom-brush transitional conformation on the surface of liposomes. This conformation was not only promoted stable delivery, but also shielded the capture of mucus more favorably, leading to a more unrestricted transportation in mucus. The further in vivo experimental results demonstrated the rapid distribution of liposomes, which gradually appeared both in the superficial and deep glandular of mucosa and gland cells at 1 h and absorbed into the cell cytoplasm at 6 h. The 5% PEG-Lip with the mushroom-brush transitional configuration recalled abnormal organ index and improved inflammation and intestinal metaplasia. The modified PEG conformation assay presented here was more suitable for liposomes. This PEG-modified liposome system has potential of mucus-penetrating and provides a strategy for local treatment of gastric mucosal intestinal metaplasia.

Targeted Delivery of Cisplatin by Gold Nanoparticles: The Influence of Nanocarrier Surface Modification Type on the Efficiency of Drug Binding Examined by CE-ICP-MS/MS

Spherical gold nanoparticles (GNPs), whose unique properties regarding biomedical applications were broadly investigated, are an object of interest as nanocarriers in drug targeted delivery systems (DTDSs). The possibility of surface functionalization, especially in enabling longer half-life in the bloodstream and enhancing cellular uptake, provides an opportunity to overcome the limitations of popular anticancer drugs (such as cisplatin) that cause severe side effects due to their nonselective transportation. Herein, we present investigations of gold nanoparticle–cisplatin systems formation (regarding reaction kinetics and equilibrium) in which it was proved that the formation efficiency and stability strongly depend on the nanoparticle surface functionalization. In this study, the capillary electrophoresis hyphenated with inductively coupled plasma tandem mass spectrometry (CE-ICP-MS/MS) was used for the first time to monitor gold–drug nanoconjugates formation. The research included optimizing CE separation conditions and determining reaction kinetics using the CE-ICP-MS/MS developed method. To characterize nanocarriers and portray changes in their physicochemical properties induced by the surface’s processes, additional hydrodynamic size and ζ-potential by dynamic light scattering (DLS) measurements were carried out. The examinations of three types of functionalized GNPs (GNP-PEG-COOH, GNP-PEG-OCH₃, and GNP-PEG-biotin) distinguished the essential differences in drug binding efficiency and nanoconjugate stability.

Recent Advances in Ovarian Cancer: Therapeutic Strategies, Potential Biomarkers, and Technological Improvements

Aggressive and recurrent gynecological cancers are associated with worse prognosis and a lack of effective therapeutic response. Ovarian cancer (OC) patients are often diagnosed in advanced stages, when drug resistance, angiogenesis, relapse, and metastasis impact survival outcomes. Currently, surgical debulking, radiotherapy, and/or chemotherapy remain the mainstream treatment modalities; however, patients suffer unwanted side effects and drug resistance in the absence of targeted therapies. Hence, it is urgent to decipher the complex disease biology and identify potential biomarkers, which could greatly contribute to making an early diagnosis or predicting the response to specific therapies. This review aims to critically discuss the current therapeutic strategies for OC, novel drug-delivery systems, and potential biomarkers in the context of genetics and molecular research. It emphasizes how the understanding of disease biology is related to the advancement of technology, enabling the exploration of novel biomarkers that may be able to provide more accurate diagnosis and prognosis, which would effectively translate into targeted therapies, ultimately improving patients’ overall survival and quality of life.

Methodology for characterization of platinum-based drug's targeted delivery nanosystems

Conventional anticancer therapies exploiting platinum-based drugs rely principally on the intravascular injection of the therapeutic agent. The anticancer drug is distributed throughout the body by the systemic blood circulation undergoing cellular uptake, rapid clearance and excretion. Consequently, only a small portion of the platinum-based drug reaches the tumor site, which is associated with severe side effects. For this reason, targeted delivery systems are of great need since they offer enhanced and selective delivery of a drug to cancerous cells making the therapy safe and more effective. Up to date, a variety of the Pt-based drug targeted delivery systems (Pt-based DTDSs) utilizing nanomaterials have been developed and tested using a range of analytical techniques that provided essential information on their synthesis, stability, biodistribution and cytotoxicity. Here we summarize those experimental techniques indicating their applicability at different stages of the research, as well as pointing out their strengths, advantages, drawbacks and limitations. Also, the existing strategies and approaches are critically reviewed with the objective to reveal and give rise to the development of the analytical methodology suitable for reliable Pt-based DTDSs characterization which would eventually result in novel therapies and better patients' outcomes.

Aggregation affects optical properties and photothermal heating of gold nanospheres

Laser heating of gold nanospheres (GNS) is increasingly prevalent in biomedical applications due to tunable optical properties that determine heating efficiency. Although many geometric parameters (i.e. size, morphology) can affect optical properties of individual GNS and their heating, no specific studies of how GNS aggregation affects heating have been carried out. We posit here that aggregation, which can occur within some biological systems, will significantly impact the optical and therefore heating properties of GNS. To address this, we employed discrete dipole approximation (DDA) simulations, Ultraviolet-Visible spectroscopy (UV-Vis) and laser calorimetry on GNS primary particles with diameters (5, 16, 30 nm) and their aggregates that contain 2 to 30 GNS particles. DDA shows that aggregation can reduce the extinction cross-section on a per particle basis by 17-28%. Experimental measurement by UV-Vis and laser calorimetry on aggregates also show up to a 25% reduction in extinction coefficient and significantly lower heating (~ 10%) compared to dispersed GNS. In addition, comparison of select aggregates shows even larger extinction cross section drops in sparse vs. dense aggregates. This work shows that GNS aggregation can change optical properties and reduce heating and provides a new framework for exploring this effect during laser heating of nanomaterial solutions.

Assembly and Detachment of Hyaluronic Acid on a Protein-Conjugated Gold Nanoparticle

The assembly-disassembly of hyaluronic acid (HA) with a bovine serum albumin-conjugated gold nanoparticle (BSA-AuNP) was demonstrated using a gas-phase electrophoresis approach, electrospray-differential mobility analysis (ES-DMA). Physical sizes, number and mass concentrations, and degrees of aggregation of HA, BSA, and AuNP were successfully quantified using ES-DMA hyphenated with inductively coupled plasma mass spectrometry. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy was employed complementarily for an orthogonal characterization of the assembly of HA with BSA-AuNP and the subsequent HA detachment. The results show that the surface packing density of HA on BSA-AuNP was proportional to the concentration of HA (C_HA) when C_HA ≤ 5 × 10^-3 μmol/L, and the equilibrium binding constant of HA on BSA-AuNP was identified as ≈ 4 × 10⁵ L/mol at pH 3. The pH-sensitive and enzyme-induced detachments of HA from BSA-AuNP were both successfully characterized using ES-DMA and ATR-FTIR. In the absence of enzymatic catalysis, the rate constant of HA detachment (k) was shown to increase by at least 3.7 times on adjusting the environmental acidity from pH 3 to pH 7. A significant enzyme-induced HA detachment was identified at pH 7, showing a remarkable increase of k by at least two times in the presence of an enzyme. This work provides a proof of concept for assembly of HA-based hybrid colloidal nanomaterials through the tuning of surface chemistry in the aqueous phase with the ability of in situ quantitative characterization, which has shown promise for the development of a variety of HA-derivative biomedical applications (e.g., drug delivery).

Preparation and characterization of novel anti-inflammatory biological agents based on piroxicam-loaded poly-ε-caprolactone nano-particles for sustained NSAID delivery

Piroxicam (PX), a main member of non-steroidal anti-inflammatory drugs (NSAIDs), is mainly used orally, which causes side effects of the gastrointestinal tract. It also has systemic effects when administered intramuscularly. Intra-articular (IA) delivery and encapsulation of PX in biodegradable poly-ε-caprolactone (PCL) nanoparticles (NPs) offer potential advantages over conventional oral delivery. The purpose of this study is the development of a new type of anti-inflammatory bio-agents containing collagen and PX-loaded NPs, as an example for an oral formulation replacement, for the prolonged release of PX. In this study, the PX was encapsulated in PCL NPs (size 102.7 ± 19.37 nm, encapsulation efficiency 92.83 ± 0.4410) by oil-in-water (o/w) emulsion solvent evaporation method. Nanoparticles were then characterized for entrapment efficiency, percent yield, particle size analysis, morphological characteristics, and in vitro drug release profiles. Eventually, the NPs synthesized with collagen were conjugated so that the NPs were trapped in the collagen sponges using a cross-linker. Finally, biocompatibility tests showed that the anti-inflammatory agents made in this study had no toxic effect on the cells. Based on the results, it appears that PX-loaded PCL NPs along with collagen (PPCLnp-Coll) can be promising for IA administration based on particulate drug delivery for the treatment of arthritis.

Advances in Gold Nanoparticle-Based Combined Cancer Therapy

According to the global cancer observatory (GLOBOCAN), there are approximately 18 million new cancer cases per year worldwide. Cancer therapies are largely limited to surgery, radiotherapy, and chemotherapy. In radiotherapy and chemotherapy, the maximum tolerated dose is presently being used to treat cancer patients. The integrated development of innovative nanoparticle (NP) based approaches will be a key to address one of the main issues in both radiotherapy and chemotherapy: normal tissue toxicity. Among other inorganic NP systems, gold nanoparticle (GNP) based systems offer the means to further improve chemotherapy through controlled delivery of chemotherapeutics, while local radiotherapy dose can be enhanced by targeting the GNPs to the tumor. There have been over 20 nanotechnology-based therapeutic products approved for clinical use in the past two decades. Hence, the goal of this review is to understand what we have achieved so far and what else we can do to accelerate clinical use of GNP-based therapeutic platforms to minimize normal tissue toxicity while increasing the efficacy of the treatment. Nanomedicine will revolutionize future cancer treatment options and our ultimate goal should be to develop treatments that have minimum side effects, for improving the quality of life of all cancer patients.

Fe3O4@SiO2@Au nanoparticles for MRI-guided chemo/NIR photothermal therapy of cancer cells

Novel functionalized (biofunctionalization followed by cisplatin immobilization) Fe3O4@SiO2@Au nanoparticles (NPs) were designed. The encapsulation of Fe3O4 cores inside continuous SiO2 shells preserves their initial structure and strong magnetic properties, while the shell surface can be decorated by small Au NPs, and then cisplatin (cPt) can be successfully immobilized on their surface. The fabricated NPs exhibit very strong T 2 contrasting properties for magnetic resonance imaging (MRI). The functionalized Fe3O4@SiO2@Au NPs are tested for a potential application in photothermal cancer therapy, which is simulated by irradiation of two colon cancer cell lines (SW480 and SW620) with a laser (λ = 808 nm, W = 100 mW cm-2). It is found that the functionalized NPs possess low toxicity towards cancer cells (∼10-15%), which however could be drastically increased by laser irradiation, leading to a mortality of the cells of ∼43-50%. This increase of the cytotoxic properties of the Fe3O4@SiO2@Au NPs, due to the synergic effect between the presence of cPt plus Au NPs and laser irradiation, makes these NPs perspective agents for potential (MRI)-guided stimulated chemo-photothermal treatment of cancer.

In Vitro Drug Release and Biocatalysis from pH-Responsive Gold Nanoparticles Synthesized Using Doxycycline

pH-sensitive doxycycline gold nanoparticles (doxy-AuNPs) are reported here to act as effective drug nanocarriers and as biocatalysts. The AuNPs were synthesized with doxy as the reducing and capping agent. Various parameters were optimized to find the best conditions for the synthesis of doxy-AuNPs, and these were characterized with UV-vis, X-ray diffraction (XRD), FTIR, and transmission electron microscopy (TEM). Doxy-AuNPs were then loaded with the anticancer drug doxorubicin (DOX), where 70% of the initially available drug was loaded within 24 h. Furthermore, pH-dependent drug release was measured at 60% with in vitro measurements in phosphate-buffered saline (PBS). In addition, the doxy-AuNPs were applied as a biocatalyst. Oxidation of dopamine was taken as a model reaction to determine the catalytic activity of doxy-AuNPs. Almost complete oxidation of dopamine occurred in 5 min, which indicates the fast response of synthesized doxy-AuNPs as a biocatalyst. Hence, doxy-AuNPs are a versatile platform for drug loading and biocatalyst.

Magnetogel Nanospheres Composed of Cisplatin-Loaded Alginate/B-Cyclodextrin as Controlled Release Drug Delivery

Purpose: The main aim of the present study was to design, fabrication and physicochemical characteristics of the magnetogel nanospheres as carriers for Cisplatin in the in vitro environment.

Methods: Magnetic nanospheres were synthesized by using a chemical co-precipitation method and coated by sodium alginate through double emulsion method. Then cisplatin was encapsulated into β-cyclodextrin -sodium alginate grafted magnetic nanospheres. The physicochemical properties of the sodium alginate grafted magnetic nanospheres were characterized by using FTIR, particle size analyzing, vibrating sample magnetometry, thermogravimetric and SEM analysis. Also the drug entrapment efficiency, content and in vitro release profile were investigated.

Results: Size distribution results revealed that the particles size was distributed in the range of 50± nm. Also morphological properties showed that particles are separated and spherical with the grafted layers of the polymer. The release profile data were in the acceptable range compared to the blank (cisplatin solution).

Conclusion: It could be concluded that the sodium alginate grafted magnetic nanospheres could act as a slow and controlled release system to deliver cisplatin.

Nano-Based Systems and Biomacromolecules as Carriers for Metallodrugs in Anticancer Therapy

Since the discovery of cisplatin and its potency in anticancer therapy, the development of metallodrugs has been an active area of research. The large choice of transition metals, oxidation states, coordinating ligands, and different geometries, allows for the design of metal-based agents with unique mechanisms of action. Many metallodrugs, such as titanium, ruthenium, gallium, tin, gold, and copper-based complexes have been found to have anticancer activities. However, biological application of these agents necessitates aqueous solubility and low systemic toxicity. This minireview highlights the emerging strategies to facilitate the in vivo application of metallodrugs, aimed at enhancing their solubility and bioavailability, as well as improving their delivery to tumor tissues. The focus is on encapsulating the metal-based complexes into nanocarriers or coupling to biomacromolecules, generating efficacious anticancer therapies. The delivery systems for complexes of platinum, ruthenium, copper, and iron are discussed with most recent examples.

Aerosol-Based Self-Assembly of a Ag-ZnO Hybrid Nanoparticle Cluster with Mechanistic Understanding for Enhanced Photocatalysis

A gas-phase-controlled synthetic approach is demonstrated to fabricate Ag-ZnO hybrid nanostructure as a high-performance catalyst for photodegradation of water pollutants. The degradation of rhodamine B (RhB) was used as representative, which were tested and evaluated with respect to the environmental pH and the presence of dodecyl sulfate corona on the surface of the catalyst. The results show that a raspberry-structure Ag-ZnO hybrid nanoparticle cluster was successfully synthesized via gas-phase evaporation-induced self-assembly. The photodegradation activity increased significantly (20×) by using the Ag-ZnO hybrid nanoparticle cluster as a catalyst. A surge of catalytic turnover frequency of ZnO nanoparticle cluster (>20×) was observed through the hybridization with silver nanoparticles. The dodecyl sulfate corona increased the photocatalytic activity of the Ag-ZnO hybrid nanoparticle cluster, especially at the acidic and neutral pH environments (maximum 6×), and the enhancement in catalytic activity was attributed to the improved colloidal stability of ZnO-based nanoparticle cluster under the interaction with RhB. Our work provides a generic route of facile synthesis of the Ag-ZnO hybrid nanoparticle cluster with a mechanistic understanding of the interface reaction for enhancing photocatalysis toward the degradation of water pollutants.