Study on β-cyclodextrin-complexed nanogels with improved thermal response for anticancer drug delivery

Smart chitosan nanogel for targeted doxorubicin delivery, ensuring precise release, and minimizing side effects in Ehrlich ascites carcinoma-bearing mice

In recent decades, bio-polymeric nanogels have become a forefront in medical research as innovative in-vivo drug carriers. This study introduces a pH-sensitive chitosan nanoparticles/P(N-Isopropylacrylamide-co-Acrylic acid) nanogel (CSNPs/P(NIPAm-co-AAc)), making significant advancements. The nanogel effectively encapsulated doxorubicin hydrochloride (Dx. HCl), a model drug, within its compartments through electrostatic binding. Comparing nano chitosan (CSNPs) before and after integrating copolymerized P(NIPAm-co-AAc), highlighting an improved and adaptable nanogel structure with responsive behaviors. The intraperitoneal delivery of Dx-loaded nanogel (Dx@N.gel) to Ehrlich ascites carcinoma (Eh)-bearing mice at doses equivalent to 1.5 and 3 mg/kg of Dx per day for 14 days exhibited superiority over the administration of free Dx. Dx@N.gel demonstrated heightened anticancer activity, significantly improving mean survival rates in Eh mice. The nanogel's multifaceted defense mechanism mitigated oxidative stress, inhibited lipid peroxidation, and curbed nitric oxide formation induced by free Dx. It effectively countered hepatic DNA deterioration, normalized elevated liver and cardiac enzyme levels, and ameliorated renal complications. This pH-responsive CSNPs/P(NIPAm-co-AAc) nanogel loaded with Dx represents a paradigm shift in antitumor drug delivery. Its efficacy and ability to minimize side effects, contrasting sharply with those of free Dx, offer a promising future where potent cancer therapies seamlessly align with patient well-being.

Temperature-Sensitive Aerogel Using Bagasse Carboxylated Cellulose Nanocrystals/N-Isopropyl Acrylamide for Controlled Release of Pesticides

Temperature-sensitive carboxylated cellulose nanocrystals/N-isopropyl acrylamide aerogels (CCNC-NIPAMs) were developed as novel pesticide-controlled release formulas. Ammonium persulfate (APS) one-step oxidation was used to prepare bagasse-based CCNCs, and then the monomer N-isopropyl acrylamide (NIPAM) was successfully introduced and constructed into the temperature-sensitive CCNC-NIPAMs through polymerization. The results of the zeta potential measurement and Fourier infrared transform spectrum (FTIR) show that the average particle size of the CCNCs was 120.9 nm, the average surface potential of the CCNCs was -34.8 mV, and the crystallinity was 62.8%. The primary hydroxyl group on the surface of the CCNCs was replaced by the carboxyl group during oxidation. The morphology and structure of CCNC-NIPAMs were characterized via electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), compression performance, porosity analysis, and thermogravimetric (TG) analysis. The results demonstrate that CCNC-NIPAM has a high porosity and low density, as well as good thermal stability, which is conducive to loading and releasing pesticides. In the swelling, drug loading, and controlled release process, the CCNC-NIPAM exhibited significant temperature sensitivity. Under the same NIPAM reaction amount, the equilibrium swelling rate of the CCNC-NIPAM first increased and then decreased with increasing temperature, and the cumulative drug release ratio of the CCNC-NIPAM at 39 °C was significantly higher than that at 25 °C. The loading efficiency of the CCNC-NIPAM on the model drug thiamethoxam (TXM) was up to 23 wt%, and the first-order model and Korsmyer-Peppas model could be well-fitted in the drug release curves. The study provides a new method for the effective utilization of biomass and pesticides.

Injectable Thermoresponsive Hydrogels for Cancer Therapy: Challenges and Prospects

The enervating side effects of chemotherapeutic drugs have necessitated the use of targeted drug delivery in cancer therapy. To that end, thermoresponsive hydrogels have been employed to improve the accumulation and maintenance of drug release at the tumour site. Despite their efficiency, very few thermoresponsive hydrogel-based drugs have undergone clinical trials, and even fewer have received FDA approval for cancer treatment. This review discusses the challenges of designing thermoresponsive hydrogels for cancer treatment and offers suggestions for these challenges as available in the literature. Furthermore, the argument for drug accumulation is challenged by the revelation of structural and functional barriers in tumours that may not support targeted drug release from hydrogels. Other highlights involve the demanding preparation process of thermoresponsive hydrogels, which often involves poor drug loading and difficulties in controlling the lower critical solution temperature and gelation kinetics. Additionally, the shortcomings in the administration process of thermosensitive hydrogels are examined, and special insight into the injectable thermosensitive hydrogels that reached clinical trials for cancer treatment is provided.

Different Applications of Temperature responsive nanogels as a new drug delivery system mini review

Temperature-sensitive drug delivery systems (TSDDS) are one of the systems that have received more attention in medical science these days due to their advantages. As these systems are sensitive to temperature, drug delivery to the target becomes more specific. Temperature-sensitive nanogels have many applications, including microbial infections, cancer therapy, transdermal use and tissue repair. These systems are characterized by minimal toxicity, improved therapeutic efficacy and reduced exposure to normal cells. This mini-review is prepared with different types of temperature-sensitive nanogel formation, release mechanisms, and their different applications. Various systems reported under these categories for targeted and controlled delivery of different classes of drugs, such as anti-cancer and antibiotic drugs with special emphasis on anti-cancer drugs and tissue healing, are discussed in this mini-review.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

Dextrin-Based Nanohydrogels for Rokitamycin Prolonged Topical Delivery

Macrolides are widely used antibiotics with a broad spectrum of activity. The development of drug carriers to deliver this type of antibiotics has attracted much research. The present study aims at developing new swellable dextrin-based nanohydrogels for the topical delivery of rokitamycin, as model macrolide. Rokitamycin is a synthetic analogous of macrolides with advantageous characteristics as far as bacterial uptake and post-antibiotic effect are concerned. It is also indicated for the treatment of severe infections caused by Acanthamoeba and for topical infections. The nanohydrogels have been prepared from two types of cross-linked polymers obtained by using β-cyclodextrin or Linecaps^® was provided by the Roquette Italia SPA (Cassano Spinola, Al, Italy) as building blocks. The cross-linked polymers have been then formulated into aqueous nanosuspensions refined and tuned to achieve the incorporation of the drug. Cross-linked β-cyclodextrin (β-CD) and Linecaps^® (LC) polymers formed dextrin-based nanohydrogels with high swelling degree and mucoadhesion capability. Rokitamycin was loaded into the nanohydrogels displaying an average size around 200 nm with negative surface charge. In vitro kinetic profiles of free and loaded drug in nanohydrogels were compared at two pH levels. Interestingly, a sustained and controlled release was obtained at skin pH level due to the high degree of swelling and a pH responsiveness possibly. The results collected suggest that these nanohydrogels are promising for the delivery of rokitamycin and may pave the way for the topical delivery of other macrolide antibiotics.

Microgels and Nanogels for the Delivery of Poorly Water-Soluble Drugs

While microgels and nanogels are most commonly used for the delivery of hydrophilic therapeutics, the water-swollen structure, size, deformability, colloidal stability, functionality, and physicochemical tunability of microgels can also offer benefits for addressing many of the barriers of conventional vehicles for the delivery of hydrophobic therapeutics. In this review, we describe approaches for designing microgels with the potential to load and subsequently deliver hydrophobic drugs by creating compartmentalized microgels (e.g., core-shell structures), introducing hydrophobic domains in microgels, leveraging host-guest interactions, and/or applying "smart" environmentally responsive materials with switchable hydrophobicity. In particular, the challenge of promoting hydrophobic drug loading without compromising the inherent advantages of microgels as delivery vehicles and ensuring practically relevant release kinetics from such structures is highlighted, with an eye toward the practical translation of such vehicles to the clinic.

The thermal/pH-sensitive drug delivery system encapsulated by PAA based on hollow hybrid nanospheres with two silicon source

The synthesis of drug delivery systems based on hollow mesoporous silica nanoparticles (MSNs) is still a major challenge. In this work, the hollow hybrid MSNs were successfully prepared by cetyltrimethylammonium bromide-directed sol-gel process and one-step hydrothermal treatment process. The hollow hybrid MSNs had hybrid ethane-bridged frameworks with the uniform particle size (250 nm) and mesoporous pore diameter (3.7 nm). The polyacrylic acid (PAA) encapsulated drug delivery system based on hollow hybrid MSNs was prepared by using silanization, surface modification, doxorubicin hydrochloride (DOX) loading, and PAA coating. Drug encapsulation and release behavior at different temperatures and pH were studied by using DOX as a model guest molecule. The results displayed that the modified hollow ethane-bridged MSNs possessed good biocompatibility and excellent thermal/pH-dual-sensitive drug release property. This novel thermal/pH-sensitive drug delivery system based on hollow ethane-bridged MSNs has the advantages of feasible synthesis, no cytotoxicity, and good drug loading capacity, which may have potential applications in the anticancer therapy.

Nanogels for Skin Cancer Therapy via Transdermal Delivery: Current Designs

BACKGROUND

Recently, several strategies have been proposed for skin cancer therapy by transdermal delivery, and particularly the use of nanotechnology.

METHODS

This process disrupts the stratum corneum to deliver a drug through the skin, allowing it to accumulate at the tumor site.

RESULTS

Nanogels are drug delivery systems that can be applied to many diseases. Nanogel engineering has been widely studied for use in drug delivery, particularly in cancer theranostics. This review summarizes specific strategies for using nanogels to treat skin cancer, a topic that is limited in recent literature.

CONCLUSION

Advanced techniques for effective skin cancer therapy based on the nanogel's penetration and cellular uptake abilities will be discussed. Moreover, techniques for penetrating the skin, as well as drug release, permeation studies, and microscopic observations, will also be discussed.

Hybrid mesoporous silica nanospheres modified by poly (NIPAM-co-AA) for drug delivery

The synthesis of drug delivery systems based on surface-modified mesoporous silica hollow structures remains a huge challenge. In this paper, we have obtained hollow mesoporous silica nanoparticles (MSNs) by surfactant directed sol-gel assisted hydrothermal treatment. The MSNs have the inorganic-organic hybrid frameworks with uniform diameter distribution (260 nm), and their specific surface area, mesoporous size and pore volume are 540 m² g^-1, 3.7 nm, 0.58 cm³ g^-1, respectively. It was proved that the preparation of hollow ethane-bridged nanospheres with two silicon source was due to the high crosslinking of the silicone interface and hydrothermal treatment, providing a new approach for the study of drug-loaded and controlled release behavior. Based on the synthesis of MSNs, MSNs were modified by methacryloxy propyl trimethoxyl silane (MPS) on the surface of MSNs. Then N-isopropylacryamide (NIPAM) and acrylic acid (AA) were grafted onto the surface of modified MSNs. The hollow ethane-bridged PNA-MSNs (poly (NIPAM-co-acrylic acid)-MSNs) with two silicon source were prepared successfully. Due to their distinctive hollow structure, PNA-MSNs demonstrated high drug encapsulation efficiency (70.4% ± 2.9%). The experiment results proved that the modified hollow nanoparticles not only had good biocompatibility and stability, but also possessed pH-/thermal-dual responsiveness in drug release.

Evaluation of cationic core-shell thermoresponsive poly(N-vinylcaprolactam)-based microgels as potential drug delivery nanocarriers

The present work investigates the potentiality of poly(N-vinyl caprolactam) (PVCL)-based thermoresponsive microgels decorated with cationic polymer brushes as drug delivery carriers. The effect of physico-chemical features of the colloids on cell viability response have to be carefully investigated to establish the range of suitable hydrodynamic diameters, crosslinking densities, lengths and ratios of the cationic polyelectrolyte shell which allow their efficient and effective use for cargo loading, transport and delivery. The colloidal stability of all cationic thermoresponsive microgels is maintained over several days of incubation at 37 °C in biological mimicking medium (Dulbecco's Modified Eagle's Medium supplemented with fetal bovine serum). The thin cationic polymer shell covalently anchored does not hinder the all range of microgels to be biocompatible while the higher cytotoxicity of the doxorubicin-loaded microgels on HeLa cells proves their anti-tumor activity. The core-shell PVCL drug delivery nanocarriers allow a sustained release of doxorubicin with a slightly higher viability of HeLa cells incubated in the presence of DOXO-loaded microgels compared to the free DOXO. The nature of the endocytosis pathway is investigated through a quantification of the extent of the cellular survival rate in the presence of various cellular uptake inhibitors. A clathrin-dependent internalization was observed.