Biodegradable poly(D,L-lactide-co-glycolide)/poly(L-γ-glutamic acid) nanoparticles conjugated to folic acid for targeted delivery of doxorubicin

Harnessing the Potential of PLGA Nanoparticles for Enhanced Bone Regeneration

Recently, nanotechnologies have become increasingly prominent in the field of bone tissue engineering (BTE), offering substantial potential to advance the field forward. These advancements manifest in two primary ways: the localized application of nanoengineered materials to enhance bone regeneration and their use as nanovehicles for delivering bioactive compounds. Despite significant progress in the development of bone substitutes over the past few decades, it is worth noting that the quest to identify the optimal biomaterial for bone regeneration remains a subject of intense debate. Ever since its initial discovery, poly(lactic-co-glycolic acid) (PLGA) has found widespread use in BTE due to its favorable biocompatibility and customizable biodegradability. This review provides an overview of contemporary advancements in the development of bone regeneration materials using PLGA polymers. The review covers some of the properties of PLGA, with a special focus on modifications of these properties towards bone regeneration. Furthermore, we delve into the techniques for synthesizing PLGA nanoparticles (NPs), the diverse forms in which these NPs can be fabricated, and the bioactive molecules that exhibit therapeutic potential for promoting bone regeneration. Additionally, we addressed some of the current concerns regarding the safety of PLGA NPs and PLGA-based products available on the market. Finally, we briefly discussed some of the current challenges and proposed some strategies to functionally enhance the fabrication of PLGA NPs towards BTE. We envisage that the utilization of PLGA NP holds significant potential as a potent tool in advancing therapies for intractable bone diseases.

Novel role of folate (vitamin B9) released by fermenting bacteria under Human Intestine like environment

The anaerobic region of the gastrointestinal (GI) tract has been replicated in the anaerobic chamber of a microbial fuel cell (MFC). Electroactive biomolecules released by the facultative anaerobes (Providencia rettgeri) under anoxic conditions have been studied for their potential role for redox balance. MALDI study reveals the presence of vitamin B9 (folate), 6-methylpterin, para-aminobenzoic acid (PABA) and pteroic acid called pterin pool. ATR-FTIR studies further confirm the presence of the aromatic ring and side chains of folate, 6-methylpterin and PABA groups. The photoluminescence spectra of the pool exhibit the maximum emission at 420, 425, 440, and 445 nm when excited by 310, 325, 350, and 365 nm wavelengths (day 20 sample) highlighting the presence of tunable bands. The cyclic voltammetric studies indicate the active participation of pterin pool molecules in the transfer of electrons with redox potentials at - 0.2 V and - 0.4 V for p-aminobenzoate and pterin groups, respectively. In addition, it is observed that under prolonged conditions of continuous oxidative stress (> 20 days), quinonoid tetrahydrofolate is formed, leading to temporary storage of charge. The results of the present study may potentially be useful in designing effective therapeutic strategies for the management of various GI diseases by promoting or blocking folate receptors.

Liposomes for Cancer Theranostics

Cancer is one of the most well-studied diseases and there have been significant advancements over the last few decades in understanding its molecular and cellular mechanisms. Although the current treatments (e.g., chemotherapy, radiotherapy, gene therapy and immunotherapy) have provided complete cancer remission for many patients, cancer still remains one of the most common causes of death in the world. The main reasons for the poor response rates for different cancers include the lack of drug specificity, drug resistance and toxic side effects (i.e., in healthy tissues). For addressing the limitations of conventional cancer treatments, nanotechnology has shown to be an important field for constructing different nanoparticles for destroying cancer cells. Due to their size (i.e., less than 1 μm), nanoparticles can deliver significant amounts of cancer drugs to tumors and are able to carry moieties (e.g., folate, peptides) for targeting specific types of cancer cells (i.e., through receptor-mediated endocytosis). Liposomes, composed of phospholipids and an interior aqueous core, can be used as specialized delivery vehicles as they can load different types of cancer therapy agents (e.g., drugs, photosensitizers, genetic material). In addition, the ability to load imaging agents (e.g., fluorophores, radioisotopes, MRI contrast media) enable these nanoparticles to be used for monitoring the progress of treatment. This review examines a wide variety of different liposomes for cancer theranostics, with the different available treatments (e.g., photothermal, photodynamic) and imaging modalities discussed for different cancers.

Chemo-radiotherapy with 177Lu-PLGA(RGF)-CXCR4L for the targeted treatment of colorectal cancer

Introduction

More than 1.9 million new cases of colorectal cancer and 935,000 deaths were estimated to have occurred worldwide in 2020. Therapies for metastatic colorectal cancer include cytotoxic chemotherapy and targeted therapies in multiple lines of treatment. Nevertheless, the optimal use of these agents has not yet been resolved. Regorafenib (RGF) is an Food and Drug Administration (FDA)-authorized multikinase inhibitor indicated for patients with metastatic colorectal cancer, non-responding to priority lines of chemotherapy and immunotherapy. Nanoparticles have been used in specific applications, such as site-specific drug delivery systems, cancer therapy, and clinical bioanalytical diagnostics. C-X-C Chemokine receptor type 4 (CXCR4) is the most widely-expressed chemokine receptor in more than 23 human cancer types, including colorectal cancer. This research aimed to synthesize and preclinically evaluate a targeted nanosystem for colorectal cancer chemo-radiotherapy using RGF encapsulated in Poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles coated with a CXCR4 ligand (CXCR4L) and 177Lu as a therapeutic β-emitter.

Methods

Empty PLGA and PLGA(RGF) nanoparticles were prepared using the microfluidic method, followed by the DOTA and CXCR4L functionalization and nanoparticle radiolabeling with 177Lu. The final nanosystem gave a particle size of 280 nm with a polydispersity index of 0.347. In vitro and in vivo toxicity effects were assessed using the HCT116 colorectal cancer cell line.

Results

177Lu-PLGA(RGF)-CXCR4L nanoparticles decreased cell viability and proliferation by inhibiting Erk and Akt phosphorylation and promoting apoptosis. Moreover, in vivo administration of 177Lu-PLGA(RGF)-CXCR4L significantly reduced tumor growth in an HCT116 colorectal cancer xenograft model. The biokinetic profile showed hepatic and renal elimination.

Discussion

Data obtained in this research justify additional preclinical safety trials and the clinical evaluation of 177Lu-PLGA(RGF)-CXCR4L as a potential combined treatment of colorectal cancer.

Doxorubicin Conjugates: An Efficient Approach for Enhanced Therapeutic Efficacy with Reduced Side Effects

Continuous drug delivery modification is the scientific approach and is a basic need for the efficient therapeutic efficacy of active drug molecules. Polymer-drug conjugates have long been a hallmark of the drug delivery sector, with various conjugates on the market or in clinical trials. Improved drug solubilization, extended blood circulation, decreased immunogenicity, controlled release behavior, and increased safety are the advantages of conjugating drugs to the polymeric carrier like polyethylene glycol (PEG). Polymer therapies have evolved over the last decade, resulting in polymer-drug conjugates with diverse topologies and chemical properties. Traditional nondegradable polymeric carriers like PEG and hydroxy propyl methacrylate have been clinically employed to fabricate polymer-drug conjugates. Still, functionalized polymer-drug conjugates are increasingly being used to increase localized drug delivery and ease of removal. Researchers have developed multifunctional carriers that can "see and treat" patients using medicinal and diagnostic chemicals. This review focused on the various conjugation approaches for attaching the doxorubicin to different polymers to achieve enhanced therapeutic efficacy, that is, increased bioavailability and reduced adverse effects.

A sequentially responsive cascade nanoplatform for increasing chemo-chemodynamic therapy

Poly(lactide-co-glycolide) (PLGA) is promising carrier material for drugs delivery in cancer therapy. However, the slow degradation and lack of targeting have greatly limited the clinical effectiveness of PLGA-based nanomedicines. Herein, we fabricated a hybrid nanosystem (3 P @ He/Pt-NPs) comprising of acid-sensitive polymer (mPOE-PLGA), active-targeting polymer (PBA-PLGA) and therapeutic agents (hemin+cisplatin) to combat these problems. In neutral environment, PEGylation can effectively improve the blood stability and circulation time of hybrid nanosystem. After reaching tumor regions, this nanosystem efficiently increased cellular uptake by dePEGylation and PBA-mediated active-targeting. Furthermore, encapsulated hemin could catalyze the oxygen bubbles generation, which remarkably increasing the drugs release rate. Subsequently, hybrid particles produced a higher cell-killing effect to lung cancer cells (A549) by the combination therapy (chemotherapy and chemodynamic therapy (CDT)). Importantly, cisplatin further amplified CDT effect by inducing H₂O₂ regeneration owing to the cascade enzymatic reactions, while hemin decreased intracellular glutathione (GSH) level, resulting in a low detoxification effect to cisplatin. Thus, hybrid particles could efficiently inhibit drug-resistant tumor growth and the inhibition rate reached 83.2%. Overall, this hybrid polymer nanosystem improve the drawbacks of PLGA-based nanocarriers, and can realize a cascading enhanced tumor treatment.

Using magnetic mesoporous silica nanoparticles armed with EpCAM aptamer as an efficient platform for specific delivery of 5-fluorouracil to colorectal cancer cells

Background: Theranostic nanoparticles with both imaging and therapeutic capacities are highly promising in successful diagnosis and treatment of advanced cancers. Methods: Here, we developed magnetic mesoporous silica nanoparticles (MSNs) loaded with 5-fluorouracil (5-FU) and surface-decorated with polyethylene glycol (PEG), and epithelial cell adhesion molecule (EpCAM) aptamer (Apt) for controlled release of 5-FU and targeted treatment of colorectal cancer (CRC) both in vitro and in vivo. In this system, Au NPs are conjugated onto the exterior surface of MSNs as a gatekeeper for intelligent release of the anti-cancer drug at acidic conditions. Results: Nanocarriers were prepared with a final size diameter of 78 nm, the surface area and pore size of SPION-MSNs were calculated as 636 m²g^-1, and 3 nm based on the BET analysis. The release of 5-FU from nanocarriers was pH-dependent, with an initial rapid release (within 6 h) followed by a sustained release for 96 h at pH 5.4. Tracking the cellular uptake by flow cytometry technique illustrated more efficient and higher uptake of targeted nanocarriers in HT-29 cells compared with non-targeted formula. In vitro results demonstrated that nanocarriers inhibited the growth of cancer cells via apoptosis induction. Furthermore, the targeted NPs could significantly reduce tumor growth in immunocompromised C57BL/6 mice bearing HT-29 tumors, similar to those injected with free 5-FU, while inducing less side effects. Conclusion: These findings suggest that application of Apt-PEG-Au-NPs@5-FU represents a promising theranostic platform for EpCAM-positive CRC cells, although further experiments are required before it can be practiced in the clinic.

The anti-tumor and renoprotection study of E-[c(RGDfK)2]/folic acid co-modified nanostructured lipid carrier loaded with doxorubicin hydrochloride/salvianolic acid A

Background

Poor in vivo targeting of tumors by chemotherapeutic drugs reduces their anti-cancer efficacy in the clinic. The discovery of over-expressed components on the tumor cell surface and their specific ligands provide a basis for targeting tumor cells. However, the differences in the expression levels of these receptors on the tumor cell surface limit the clinical application of anti-tumor preparations modified by a single ligand. Meanwhile, toxicity of chemotherapeutic drugs leads to poor tolerance to anti-tumor therapy. The discovery of natural active products antagonizing these toxic side effects offers an avenue for relieving cancer patients’ pain during the treatment process. Since the advent of nanotechnology, interventions, such as loading appropriate drug combinations into nano-sized carriers and multiple tumor-targeting functional modifications on the carrier surface to enhance the anti-tumor effect and reduce toxic and side effects, have been widely used for treating tumors.

Results

Nanocarriers containing doxorubicin hydrochloride (DOX) and salvianolic acid A (Sal A) are spherical with a diameter of about 18 nm; the encapsulation efficiency of both DOX and salvianolic acid A is greater than 80%. E-[c(RGDfK)2]/folic acid (FA) co-modification enabled nanostructured lipid carriers (NLC) to efficiently target a variety of tumor cells, including 4T1, MDA-MB-231, MCF-7, and A549 cells in vitro. Compared with other preparations (Sal A solution, NLC-Sal A, DOX solution, DOX injection, Sal A/DOX solution, NLC-DOX, NLC-Sal A/DOX, and E-[c(RGDfK)2]/FA-NLC-Sal A/DOX) in this experiment, the prepared E-[c(RGDfK)2]/FA-NLC-Sal A/DOX had the best anti-tumor effect. Compared with the normal saline group, it had the highest tumor volume inhibition rate (90.72%), the highest tumor weight inhibition rate (83.94%), led to the highest proportion of apoptosis among the tumor cells (61.30%) and the lowest fluorescence intensity of proliferation among the tumor cells (0.0083 ± 0.0011). Moreover, E-[c(RGDfK)2]/FA-NLC-Sal A/DOX had a low level of nephrotoxicity, with a low creatinine (Cre) concentration of 52.58 μmoL/L in the blood of mice, and no abnormalities were seen on pathological examination of the isolated kidneys at the end of the study. Sal A can antagonize the nephrotoxic effect of DOX. Free Sal A reduced the Cre concentration of the free DOX group by 61.64%. In NLC groups, Sal A reduced the Cre concentration of the DOX group by 42.47%. The E-[c(RGDfK)2]/FA modification reduced the side effects of the drug on the kidney, and the Cre concentration was reduced by 46.35% compared with the NLC-Sal A/DOX group. These interventions can potentially improve the tolerance of cancer patients to chemotherapy.

Conclusion

The E-[c(RGDfK)2]/FA co-modified DOX/Sal A multifunctional nano-drug delivery system has a good therapeutic effect on tumors and low nephrotoxicity and is a promising anti-cancer strategy.

Graphical Abstract

Optically traceable PLGA-silica nanoparticles for cell-triggered doxorubicin delivery

Fluorescent silica nanoparticles with a polymer shell of poly (D, L-lactide-co-glycolide) (PLGA) can provide traceable cell-triggered delivery of the anticancer drug doxorubicin (DOX), protecting the cargo while in transit and releasing it only intracellularly. PLGA with 50:50 lactide:glycolide ratio was grown by surface-initiated ring-opening polymerization (ROP) from silica nanoparticles of ca. 50 nm diameter, doped with a perylenediimide (PDI) fluorescent dye anchored to the silica structure. After loading DOX, release from the core-shell particles was evaluated in solution at physiological pH (7.4), and in human breast cancer cells (MCF-7) after internalization. The hybrid silica-PLGA nanoparticles can accommodate a large cargo of DOX, and the release in solution (PBS) due to PLGA hydrolysis is negligible for at least 72 h. However, once internalized in MCF-7 cells, the nanoparticles release the DOX cargo by degradation of the PLGA. Accumulation of DOX in the nucleus causes cell apoptosis, with the drug-loaded nanoparticles found to be as potent as free DOX. Our fluorescently traceable hybrid silica-PLGA nanoparticles with cell-triggered cargo release offer excellent prospects for the controlled delivery of anticancer drugs, protecting the cargo while in transit and efficiently releasing the drug once inside the cell.

In-situ reaction compatibilization modification of poly(butylene succinate-co-terephthalate)/polylactide acid blend films by multifunctional epoxy compound

Poly(butylene succinate-co-terephthalate) (PBST) copolyester, is a new type of biodegradable synthetic polymer material that has emerged in recent years, but it cannot meet the market requirements, because of its low strength. The high-strength and high-modulus polylactic acid (PLA) was blended with PBST to increase its strength, and the chain extender ADR-4370 was used to modify PBST/PLA films by reaction and compatibilization. Compared with the 80/20 wt% PBST/PLA films, the tensile strength after modification with 0.3 wt% ADR was increased by 21.8 % and 44.3 % in the machine direction (MD) and in the transverse direction (TD), respectively. The Water Vapor Permeability (WVP) was decreased from 10.0 × 10^-14 to 3.09 × 10^-14 g·cm/cm²·s·Pa. The compatibilization mechanism was studied by gel permeation chromatography, infrared spectroscopy, dynamic mechanical analysis, rheological analysis, and other characterization methods. The formation of the copolymer PLA-g-PBST is the most important factor to improve the compatibility of the system and the mechanical properties of the films.

IAEA Contribution to Nanosized Targeted Radiopharmaceuticals for Drug Delivery

The rapidly growing interest in the application of nanoscience in the future design of radiopharmaceuticals and the development of nanosized radiopharmaceuticals in the late 2000′s, resulted in the creation of a Coordinated Research Project (CRP) by the International Atomic Energy Agency (IAEA) in 2014. This CRP entitled ‘Nanosized delivery systems for radiopharmaceuticals’ involved a team of expert scientist from various member states. This team of scientists worked on a number of cutting-edge areas of nanoscience with a focus on developing well-defined, highly effective and site-specific delivery systems of radiopharmaceuticals. Specifically, focus areas of various teams of scientists comprised of the development of nanoparticles (NPs) based on metals, polymers, and gels, and their conjugation/encapsulation or decoration with various tumor avid ligands such as peptides, folates, and small molecule phytochemicals. The research and development efforts also comprised of developing optimum radiolabeling methods of various nano vectors using diagnostic and therapeutic radionuclides including Tc-99m, Ga-68, Lu-177 and Au-198. Concerted efforts of teams of scientists within this CRP has resulted in the development of various protocols and guidelines on delivery systems of nanoradiopharmaceuticals, training of numerous graduate students/post-doctoral fellows and publications in peer reviewed journals while establishing numerous productive scientific networks in various participating member states. Some of the innovative nanoconstructs were chosen for further preclinical applications—all aimed at ultimate clinical translation for treating human cancer patients. This review article summarizes outcomes of this major international scientific endeavor.

Recent Advances in Poly(α-L-glutamic acid)-Based Nanomaterials for Drug Delivery

Poly(α-L-glutamic acid) (PGA) is a class of synthetic polypeptides composed of the monomeric unit α-L-glutamic acid. Owing to their biocompatibility, biodegradability, and non-immunogenicity, PGA-based nanomaterials have been elaborately designed for drug delivery systems. Relevant studies including the latest research results on PGA-based nanomaterials for drug delivery have been discussed in this work. The following related topics are summarized as: (1) a brief description of the synthetic strategies of PGAs; (2) an elaborated presentation of the evolving applications of PGA in the areas of drug delivery, including the rational design, precise fabrication, and biological evaluation; (3) a profound discussion on the further development of PGA-based nanomaterials in drug delivery. In summary, the unique structures and superior properties enables PGA-based nanomaterials to represent as an enormous potential in biomaterials-related drug delivery areas.

Temozolomide nano enabled medicine: promises made by the nanocarriers in glioblastoma therapy

Glioblastoma multiforme (GBM) is abnormal cell proliferation of glial cells. GBM is the grade IV glioma brain cancer which is life-threatening to many individuals affected by this cancer. The DNA alkylating agent Temozolomide (TMZ) has the distinctiveness of being FDA approved anticancer drug for the first line treatment for GBM. However, treatment of GBM still remains a challenge. This is attributed to TMZ's toxic nature, severe side effects, and fast degradation in vivo. In addition, the lack of targeting ability increases the chances of systemic toxicities. A nano enabled targeted delivery system not only improves the efficiency of TMZ by making it cross the blood brain barrier, have specificity to target, but also reduces toxicity to healthy tissues. Over the last decade the significant advances in the area of nanotechnology applied to medicine have developed many multifunctional therapeutics. In this context, the present review article comprehends the significant progress in the field of TMZ loaded nanocarriers showing promise for futuristic nanomedicine therapies in treating GBM.

Cashew Gum Polysaccharide Nanoparticles Grafted with Polypropylene Glycol as Carriers for Diclofenac Sodium

This investigation focuses on the development and optimization of cashew gum polysaccharide (CGP) nanoparticles grafted with polypropylene glycol (PPG) as carriers for diclofenac sodium. The optimization of parameters affecting nanoparticles formulation was performed using a central composite rotatable design (CCRD). It was demonstrated that the best formulation was achieved when 10 mg of CGP was mixed with 10 μL of PPG and homogenized at 22,000 rpm for 15 min. The physicochemical characterization evidenced that diclofenac was efficiently entrapped, as increases in the thermal stability of the drug were observed. The CGP-PPG@diclofenac nanoparticles showed a globular shape, with smooth surfaces, a hydrodynamic diameter around 275 nm, a polydispersity index (PDI) of 0.342, and a zeta potential of -5.98 mV. The kinetic studies evidenced that diclofenac release followed an anomalous transport mechanism, with a sustained release up to 68 h. These results indicated that CGP-PPG nanoparticles are an effective material for the loading/release of drugs with similar structures to diclofenac sodium.

Natural bio-based monomers for biomedical applications: a review

In recent years, synthetic and semi-synthetic polymer materials have been widely used in various applications. Especially concerning biomedical applications, their biocompatibility, biodegradability, and non-toxicity have increased the interest of researchers to discover and develop new products for the well-being of humanity. Among the synthetic and semi-synthetic materials, the use of natural bio-based monomeric materials presents a possible novel avenue for the development of new biocompatible, biodegradable, and non-toxic products. The purpose of this article is to review the information on the role of natural bio-based monomers in biomedical applications. Increased eco-friendliness, biocompatibility, biodegradability, non-toxicity, and intrinsic biological activity are some of the attributes which make itaconic, succinic, citric, hyaluronic, and glutamic acids suitable potential materials for biomedical applications. Herein, we summarize the most recent advances in the field over the past ten years and specifically highlight new and interesting discoveries in biomedical applications. Natural origin acid-based bio-monomers for biomedical applications.

Doxorubicin delivery by magnetic nanotheranostics enhances the cell death in chemoresistant colorectal cancer-derived cells

Colorectal cancer (CRC) is a major cause of cancer death with a high probability of treatment failure. Doxorubicin (DOXO) is an efficient antitumor drug; however, most CRC cells show resistance to its effects. Magnetic nanoparticles (MNPs) are potential cancer management tools that can serve as diagnostic agents and also can optimize and personalize treatments. This work aims to evaluate the aptitude of magnetic nanotheranostics composed of magnetite (Fe₃O₄) nanoparticles coated with folic acid intended to the sustained release of DOXO. The administration of DOXO by means of these MNPs resulted in the enhancement of cell death respect to the free drug administration. Chromatin compaction and cytoplasmic protrusions were observed. Mitochondrial transmembrane potential disruption and increased PARP protein cleavage confirmed apoptosis. The nanosystem was also tested as a vectoring tool by exposing it to the stimuli of a static magnetic field in vitro. CRC-related magnetic nanotechnology still remains in pre-clinical trials. In this context, this contribution expands the knowledge of the behavior of MNPs in contact with in vitro models and proposes the nanodevices studied here as potential theranostic agents for the monitoring of the progress of CRC and the evolution of its treatment.

Apoptosis pathway in the combined treatment of x-ray and 5-FU-loaded triblock copolymer-coated magnetic nanoparticles

Aim: In this study, the effects of ionizing radiation and 5-fluorouracil (5-FU)-loaded triblock copolymer-coated magnetic nanoparticles (NPs) on the induction of apoptosis in HT-29 and HCT-116 were investigated. Materials & methods: The percentage of apoptotic cells and alteration of the expression of apoptotic-related proteins were evaluated in treated cells by flow cytometry and western blot analysis, respectively. Results: Combination treatment with 5-FU and radiation had a stronger effect on decreasing Bcl-2 expression and increasing expression of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP compared with each treatment alone. Conclusion: The combination of radiation and triblock copolymer-coated magnetic NPs as 5-FU drug carriers works by triggering apoptosis to improve in vitro treatment efficacy. Additional study may present the NPs as an effective approach for the treatment of colon cancer.

Poly(N-Isopropyl-Acrylamide)/Poly(γ-Glutamic Acid) Thermo-Sensitive Hydrogels Loaded with Superoxide Dismutase for Wound Dressing Application

INTRODUCTION

Chronic trauma repair is an important issue affecting people's healthy lives. Thermo-sensitive hydrogel is injectable in situ and can be used to treat large-area wounds. In addition, antioxidants play important roles in promoting wound repair.

METHODS

The purpose of this research was to prepare a novel thermo-sensitive hydrogel-poly(N-isopropyl-acrylamide)/poly(γ-glutamic acid) (PP) loaded with superoxide dismutase (SOD) to improve the effect for trauma treatment. The micromorphology of the hydrogel was observed by scanning electron microscope and the physical properties were measured. The biocompatibility of hydrogel was evaluated by MTT experiment, and the effect of hydrogel on skin wound healing was evaluated by in vivo histological staining.

RESULTS

Gelling behavior and differential scanning calorimeter outcomes showed that the PP hydrogels possessed thermo-sensitivity at physiological temperature and the phase transformation temperature was 28.2°C. The high swelling rate and good water retention were conducive to wound healing. The activity of SOD in vitro was up to 85% at 10 h, which was advantageous to eliminate the superoxide anion. MTT assay revealed that this hydrogel possessed good biocompatibility. Dressings of PP loaded with SOD (SOD-PP) had a higher wound closure rate than other treatments in vivo in diabetic rat model.

DISCUSSION

The SOD-PP thermo-sensitive hydrogels can effectively promote wound healing and have good application prospects for wound repair.

177Lu-Bombesin-PLGA (paclitaxel): A targeted controlled-release nanomedicine for bimodal therapy of breast cancer

The gastrin-releasing peptide receptor (GRPr) is overexpressed in >75% of breast cancers. ¹⁷⁷Lu-Bombesin (¹⁷⁷Lu-BN) has demonstrated the ability to target GRPr and facilitate efficient delivery of therapeutic radiation doses to malignant cells. Poly(d,l‑lactide‑co‑glycolide) acid (PLGA) nanoparticles can work as smart drug controlled-release systems activated through pH changes. Considering that paclitaxel (PTX) is a first-line drug for cancer treatment, this work aimed to synthesize and chemically characterize a novel polymeric PTX-loaded nanosystem with grafted ¹⁷⁷Lu-BN and to evaluate its performance as a targeted controlled-release nanomedicine for concomitant radiotherapy and chemotherapy of breast cancer. PLGA(PTX) nanoparticles were synthesized using the single emulsification-solvent evaporation method with PVA as a stabilizer in the presence of PTX. Thereafter, the activation of PLGA carboxylic groups for BN attachment through the Lys¹-amine group was performed. Results of the chemical characterization by FT-IR, DLS, HPLC and SEM/TEM demonstrated the successful synthesis of BN-PLGA(PTX) with a hydrodynamic diameter of 163.54 ± 33.25 nm. The entrapment efficiency of paclitaxel was 92.8 ± 3.6%. The nanosystem showed an adequate controlled release of the anticancer drug, which increased significantly due to the pH change from neutral (pH = 7.4) to acidic conditions (pH = 5.3). After labeling with ¹⁷⁷Lu and purification by ultrafiltration, ¹⁷⁷Lu-BN-PLGA(PTX) was obtained with a radiochemical purity of 99 ± 1%. In vitro and in vivo studies using MDA-MB-231 breast cancer cells (GRPr-positive) demonstrated a ¹⁷⁷Lu-BN-PLGA(PTX) specific uptake and a significantly higher cytotoxic effect for the radiolabeled nanosystem than the unlabeled BN-PLGA(PTX) nanoparticles. Using a pulmonary micrometastasis MDA-MB-231 model, the added value of ¹⁷⁷Lu-BN-PLGA(PTX) for tumor imaging was confirmed. The ¹⁷⁷Lu-BN-PLGA(PTX) nanomedicine is suitable as a targeted paclitaxel delivery system with concomitant radiotherapeutic effect for the treatment of GRPr-positive breast cancer.

Enhanced cancer therapy with pH-dependent and aptamer functionalized doxorubicin loaded polymeric (poly D, L-lactic-co-glycolic acid) nanoparticles

Aptamer based drug delivery systems are gaining the importance in anticancer therapy due to their targeted drug delivery efficiency without harming the normal cells. The present work formulated the pH-dependent aptamer functionalized polymer-based drug delivery system against human lung cancer. The prepared aptamer functionalized doxorubicin (DOX) loaded poly (D, L-lactic-co-glycolic acid) (PLGA), poly (N-vinylpyrrolidone) (PVP) nanoparticles (APT-DOX-PLGA-PVP NPs) were spherical in shape with an average size of 87.168 nm. The crystallography and presence of the PLGA (poly (D, L-lactic-co-glycolic acid)) and DOX (doxorubicin) in APT-DOX-PLGA-PVP NPs were indicated by the X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and ¹H and ¹³C nuclear magnetic resonance spectrometer (NMR). The pH-dependent aptamer AS1411 based drug release triggered the cancer cell death was evidenced by cytotoxicity assay, flow cytometry, and fluorescent microscopic imaging. In addition, the cellular uptake of the DOX was determined and the apoptosis-related signaling pathway in the A549 cells was studied by Western blot analysis. Further, the in vivo study revealed that mice treated with APT-DOX-PLGA-PVP NPs were significantly recovered from cancer as evident by mice weight and tumor size followed by the histopathological study. It was reported that the APT-DOX-PLGA-PVP NPs induced the apoptosis through the activation of the apoptosis-related proteins. Hence, the present study revealed that the APT-DOX-PLGA-PVP NPs improved the therapeutic efficiency through the nucleolin receptor endocytosis targeted drug release.

Multifunctional PEG-b-polypeptide-decorated gold nanorod for targeted combined chemo-photothermal therapy of breast cancer

The combination of chemotherapy and photothermal therapy is acknowledged as one of the most promising approaches in cancer treatment. Targeted delivery and controlled drug release are two important factors for combined chemo-photothermal therapy. In this study, a multifunctional nanoplatform based on gold nanorod (GNR) decorated with folate-conjugated poly(ethylene glycol)-b-poly(L-γ-glutamylhydrazine) (FEGGH) containing disulfide linker and dihydroxyphenyl groups was developed for targeted combined chemo-photothermal therapy of breast cancer. FEGGH was synthesized by ring-opening polymerization of γ-benzyl-l-glutamate-N-carboxyanhydride using folate/cystamine-heterobifunctionalized poly(ethylene glycol) as an initiator, following by hydrazinolysis and carbodiimide reactions. FEGGH was decorated onto GNR through Au-catechol bonds. Chemotherapeutic drug doxorubicin (DOX) was loaded onto the nanoplatform through pH-sensitive hydrazone linkage, obtaining final product FEGGH^DOX-GNR. The DOX-loaded nanoplatform displayed excellent photostability and reduction/pH dual-responsive drug release behavior. Cytological studies demonstrated the effective internalization of FEGGH^DOX-GNR into MCF-7 cells via folate-mediated endocytosis and additive therapeutic effect of combined photothermal-chemotherapy. These results indicate that our nanoplatform may be a promising strategy for targeted combined chemo-photothermal therapy of breast cancer.

Stimuli-responsive nanotheranostics intended for oncological diseases: in vitro evaluation of their target, diagnostic and drug release capabilities

This work reports an overview of required in vitro assays to evaluate nanotheranostics applications.

PLA-PEG-FA NPs for drug delivery system: Evaluation of carrier micro-structure, degradation and size-cell proliferation relationship

In this paper, the micro-structure of amphiphilic copolymer Polylactic acid-Polyethylene glycol-Folate (PLA-PEG-FA) was studied firstly by a differential scanning calorimetry (DSC). During the process of nanoparticles (NPs) preparation, we found good inter-structure consistency of polymer was the precondition for forming into stable NPs, and those with micro-phase separation structure were prepared of NPs within limits. Hemolytic test and CCK-8 assay results demonstrated the biotoxicity of both NPs and whose leaching liquor was far below related toxicity standards. Two kinds of cell, human breast cancer cell line (MCF-7) and human umbilical vein endothelial cells (EC), showed different manners in test of NPs size-cell proliferation relationship, respectively. Monitored by a nuclear magnetic resonance (NMR) and a gel permeation chromatography (GPC), the degradation behavior of NPs in aqueous solution indicated amide bond break more difficultly than ester bond, and FA classic proton peak disappeared in the third week, meanwhile lactic acid (LA) unit number became 25% of the initial. Finally the NPs was completely degraded in the eighth week. In the whole process, NPs underwent a change from compact to loose state. We hope these results will benefit to improve design of drug delivery system in nanomedicine, which could offer the selection rule for amphiphilic polymer NPs on material and size.

A Dual Bioconjugated Virus-Like Nanoparticle as a Drug Delivery System and Comparison with a pH-Responsive Delivery System

Modifications of virus-like nanoparticles (VLNPs) using chemical conjugation techniques have brought the field of virology closer to nanotechnology. The huge surface area to volume ratio of VLNPs permits multiple copies of a targeting ligand and drugs to be attached per nanoparticle. By exploring the chemistry of truncated hepatitis B core antigen (tHBcAg) VLNPs, doxorubicin (DOX) was coupled covalently to the external surface of these nanoparticles via carboxylate groups. About 1600 DOX molecules were conjugated on each tHBcAg VLNP. Then, folic acid (FA) was conjugated to lysine residues of tHBcAg VLNPs to target the nanoparticles to cancer cells over-expressing folic acid receptor (FR). The result demonstrated that the dual bioconjugated tHBcAg VLNPs increased the accumulation and uptake of DOX in the human cervical and colorectal cancer cell lines compared with free DOX, resulting in enhanced cytotoxicity of DOX towards these cells. The fabrication of these dual bioconjugated nanoparticles is simple, and drugs can be easily conjugated with a high coupling efficacy to the VLNPs without any limitation with respect to the cargo’s size or charge, as compared with the pH-responsive system based on tHBcAg VLNPs. These dual bioconjugated nanoparticles also have the potential to be modified for other combinatorial drug deliveries.

Cyclic nigerosyl-1,6-nigerose-based nanosponges: An innovative pH and time-controlled nanocarrier for improving cancer treatment

The design and structural optimisation of a novel polysaccharide-based nanomaterial for the controlled and sustained release of doxorubicin are here reported. A cross-linked polymer was obtained by reacting a tetraglucose, named cyclic nigerosyl-1-6-nigerose (CNN), with pyromellitic dianhydride. The cross-linking reaction formed solid nanoparticles, named nanosponges, able to swell as a function of the pH. Nanoparticle sizes were reduced using High Pressure Homogenization, to obtain uniform nanosuspensions. Doxorubicin was incorporated into the CNN-nanosponges in a good extent. DSC and solid state NMR analyses proved the drug interaction with the polymer matrix. In vitro studies demonstrated pH-dependent slow and prolonged release kinetics of the drug from the nanoformulation. Doxorubicin-loaded CNN-nanosponges were easily internalized in A2780 cell line. They might considered an intracellular doxorubicin reservoir, able to slowly release the drug over time. CNN-nanosponges may be promising biocompatible nanocarriers for the sustained delivery of doxorubicin with potential localised application in cancer treatments.