Biodegradable Delivery System Research Articles

Curcumin-loaded pickering emulsions based on soy protein isolate aggregates enhance diabetic wound healing

Wound healing in diabetic patients is more complex and prolonged in comparison to nondiabetic persons, and dealing with this problem has attracted considerable attention from researchers. According to its anti-inflammatory and anti-infective properties, Curcumin has a valued place in therapeutics, including wound healing. Still, its low stability and poor bioavailability are significant barriers to using its desirable properties. Hence, various biocompatible and biodegradable delivery systems have been developed to address this issue. In this study, Pickering emulsion (PE) prepared from soybean oil containing curcumin and modified SPI solution at 85 °C at pH 2.0 with 130 mM NaCl for different durations were used as a delivery system for curcumin. Changes in SPI properties were analyzed using fluorescence spectroscopy, Fourier transform infrared spectroscopy, and tensiometry methods. The prepared PEs were studied using microscopic techniques. Curcumin loading efficiency by PE was measured by UV–visible spectroscopy, and the impact of curcumin-loaded PE on wound healing was tested in diabetic rats. Spectroscopic studies and microscopy images revealed SPI amyloid-like aggregates suitable for stabilizing oil-in-water PEs. Tensiometry and creaming stability studies indicated that at least 6 h of heating (HSPI6) is necessary for optimal stability. Curcumin encapsulation efficiency was 95.7 ± 2.1 %. Curcumin-loaded PE-HSPI6 increased the healing rate of diabetic wounds in male Wistar rats by 1.46-fold. This study presents an approach for using biocompatible and biodegradable PEs to deliver hydrophobic compounds like curcumin for accelerating diabetic wound healing.

THE FORMULATION AND EVALUATION OF 6-THIOGUANINE AS A NANOSTRUCTURE LIPID CARRIER FOR THE TARGETED DELIVERY OF BREAST CANCER

Objective: The main goal was to avoid all the problems associated with usual breast cancer treatment by using 6-thioguanine as a nanostructure lipid carrier (TG-NLCS). This was accomplished by administering an effective and targeted dose of 6-thioguanine (TG) to the tumour site using a long-lasting and biodegradable delivery system. Methods: A combination of heat homogenization and ultrasonication was used to implement the emulsification process. To obtain the optimal formulation, the prepared formulations were first assessed for particle size, Polydispersity Index (PDI), zeta potential, entrapment efficiency, and drug loading capacity. Additionally, a range of physicochemical characterization techniques were employed, including dissolution studies, melting point determination, Fourier-Transform Infrared (FTIR) spectroscopy, and Field Emission Scanning Electron Microscopy (FESEM), as well as cytotoxicity assessment of TG-NLCs in MCF-7 breast cancer cells. Results: The selected formula, TG03, showed a zeta potential of-13.5±0.27 mV and a particle size of 149±0.55 nm. This was further examined using a FESEM. In the in vitro drug release study, the formula demonstrated better-controlled drug release for 48 h in comparison to other formulations. In addition, the significant anti-proliferation activity of TG-NLCs against the MCF-7 breast cancer cell line. Conclusion: Nanostructured lipid carriers (NLCs) are one type of multifunctional nanoparticle that includes many combinations of lipids and medicines for various delivery routes.

Design and fabrication of functionalized curdlan-curcumin delivery system to facilitate the therapeutic effects of curcumin on breast cancer

We developed a facile method for the fabrication of a biodegradable delivery system composed of two blocks: curdlan and curcumin. This was achieved by chemical functionalization of curdlan through tosylation, amination followed by complexation with curcumin. A comprehensive evaluation of structural characterization and component stability showed that cur-cum complex exhibited better anticancer properties with enhanced thermal properties. The cur-cum complex shows pH sensitive sustained release behaviour with higher release at acidic pH and kinetic data of drug release follows the Korsmeyer-Peppas model. The cur-cum complex has ability to block the proliferation of the MCF-7 cell line as revealed by MTT assay which showed increased toxicity of cur-cum complex against these cell lines. The results obtained from western blot analysis demonstrated that the co-administration of cur and cum effectively induced apoptosis in MCF-7 cells. This effect was observed by a considerable upregulation of the Bcl-2/Bax ratio, a decline in mRNA expression of LDHA, level of lactate and LDH activity. The results clearly depict the role of functionalized curdlan as efficient carrier for curcumin delivery with prolonged, sustained release and enhanced bioavailability, thereby improving the overall anticancer activity.

Lactic acid responsive sequential production of hydrogen peroxide and consumption of glutathione for enhanced ferroptosis tumor therapy

Ferroptosis is characterized by the lethal accumulation of lipid reactive oxygen species (ROS), which has great potential for tumor therapy. However, developing new ferroptosis-inducing strategies by combining nanomaterials with small molecule inducers is important. In this study, an enzyme-gated biodegradable natural-product delivery system based on lactate oxidase (LOD)-gated biodegradable iridium (Ir)-doped hollow mesoporous organosilica nanoparticles (HMONs) loaded with honokiol (HNK) (HNK@Ir-HMONs-LOD, HIHL) is designed to enhance ferroptosis in colon tumor therapy. After reaching the tumor microenvironment, the outer LOD dissociates and releases the HNK to induce ferroptosis. Moreover, the released dopant Ir4+ and disulfide-bridged organosilica frameworks deplete intracellular glutathione (GSH), which is followed by GSH-mediated Ir(IV)/Ir(III) conversion. This leads to the repression of glutathione peroxidase 4 (GPX4) activity and decomposition of intratumoral hydrogen peroxide (H2O2) into hydroxyl radicals (•OH) by Ir3+-mediated Fenton-like reactions. Moreover, LOD efficiently depletes lactic acid to facilitate the generation of H2O2 and boost the Fenton reaction, which in turn enhances ROS generation. With the synergistic effects of these cascade reactions and the release of HNK, notable ferroptosis efficacy was observed both in vitro and in vivo. This combination of natural product-induced and lactic acid-responsive sequential production of H2O2 as well as the consumption of glutathione may provide a new paradigm for achieving effective ferroptosis-based cancer therapy.

Development of Efficient Sodium Alginate/Polysuccinimide-Based Hydrogels as Biodegradable Acetaminophen Delivery Systems.

Efficient drug delivery systems are essential for improving patient outcomes. Acetaminophen (AP), which is a kind of oral administration, is a commonly used pain reliever and fever reducer. However, oral administration carries various health risks, especially overdose and frequent use; for instance, AP is administered approximately 4 times per day. Therefore, the aim of this study is to develop an efficient delivery system for once-daily administration by combining sodium alginate and polysuccinimide (PSI) hydrogels to delay the release of analgesic AP. PSI is a biodegradable polymer that can be used safely and effectively in drug delivery systems because it is eliminated by hydrolysis in the intestine. The use of PSI also improves the mechanical properties of hydrogels and prolongs drug release. In this study, hydrogel characterizations such as mechanical properties, drug dissolution ability, and biodegradability were measured to evaluate the hydrolysis of PSI in the intestine. Based on the results, hydrogels could be designed to improve the structural mechanical properties and to allow the drug to be completely dissolved, and eliminated from the body through PSI hydrolysis in the intestines. In addition, the release profiles of AP in the hydrogels were evaluated, and the hydrogels provided continuous release of AP for 24 h. Our research suggests that sodium alginate/PSI hydrogels can potentially serve as biodegradable delivery systems for AP. These findings may have significant implications for developing efficient drug delivery systems for other classes of drugs.

Increasing Chemotherapeutic Efficacy Using pH-Modulating and Doxorubicin-Releasing Injectable Chitosan-Poly(ethylene glycol) Hydrogels.

Modulation of pH is crucial to maintaining the chemical homeostasis of biological environments. The irregular metabolic pathways exhibited by cancer cells result in the production of acidic byproducts that are excreted and accumulate in the extracellular tumor microenvironment, reducing the pH. As a consequence of the lower pH in tumors, cancer cells increase the expression of metastatic phenotypes and chemotherapeutic resistance. A significant limitation in current cancer therapies is the inability to locally deliver chemotherapeutics, leading to significant damage to healthy cells in systemic administration. To overcome these challenges, we present an injectable chitosan-poly(ethylene glycol) hydrogel that is dual-loaded with doxorubicin and sodium bicarbonate providing alkaline buffering of extracellular acidity and simultaneous chemotherapeutic delivery to increase chemotherapeutic efficacy. We conducted in vitro studies of weak base chemotherapeutic and alkaline buffer release from the hydrogel. The release of doxorubicin from hydrogels increased in a low-pH environment and was dependent on the encapsulated sodium bicarbonate concentration. We investigated the influence of pH on the doxorubicin efficacy and viability of MCF-7 and MDA-MB-231 breast cancer cell lines. The results show a 2- to 3-fold increase in IC50 values from neutral pH to low pH, showing decreased cancer cell viability at neutral pH as compared to acidic pH. The IC50 results were shown to correlate with a decrease in intracellular uptake of doxorubicin at low pH. The proposed hydrogels were confirmed to be nontoxic to healthy MCF-10A mammary epithelial cells. Rheological studies were performed to verify that the dual-loaded hydrogels were injectable. The mechanical and release properties of the hydrogels were maintained after extended storage. The chemotherapeutic activity of doxorubicin was evaluated in the presence of the proposed pH-regulating hydrogels. The findings suggest a promising nontoxic, biodegradable hydrogel buffer delivery system that can achieve two simultaneous important goals of local acidosis neutralization and chemotherapeutic release.

A New Biodegradable Linear mPEG‐b‐poly(Schiff Base‐Acetal) Copolymer Carrier Co‐Delivery Cinnamaldehyde and Gemcitabine for Combined Anticancer Therapy

AbstractDue to significant pH difference among the healthy tissue, tumor tissue as well as intracellular endo/lysosome, constructing pH‐responsive biodegradable nanodrug delivery systems has received more and more attention. Herein, double‐end alkenylated acetal monomer (based on cinnamaldehyde (CA)) and double‐end sulfhydrylation Schiff base monomer were designed and synthesized, and three pH‐responsive biodegradable block copolymer mPEG‐b‐poly(Schiff base‐acetal) (P1), mPEG‐b‐poly(acetal) (P2), and mPEG‐b‐poly(Schiff base) (P3) were obtained by Michael addition reaction. All these polymers could be self‐assembled with gemcitabine (GEM) to form GEM‐loaded micelles. Proton nuclear magnetic resonance (1H NMR) and dynamic light scattering (DLS) experiments proved that these polymer micelles have good pH responsiveness. The size and morphology of both blank and GEM‐loaded micelles were characterized by DLS and scanning electron microscope (SEM). The GEM/P1, GEM/P2, and GEM/P3 micelles exhibited pH‐sensitive drug release properties and the GEM/P1 micelles has the relatively fastest drug release rate. Containing multiple acetal and Schiff base moieties GEM/P1 micelles showed fastest cellular internalized rate and best in vitro antitumor activity among all GEM‐loaded micelles.

Apoptosis-targeted gene therapy for non-small cell lung cancer using chitosan-poly-lactic-co-glycolic acid -based nano-delivery system and CASP8 and miRs 29A-B1 and 34A.

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide, with resistance to apoptosis being a major driver of therapeutic resistance and aggressive phenotype. This study aimed to develop a novel gene therapy approach for NSCLC by targeting resistance to apoptosis. Loss of function mutations of caspase 8 (CASP8) and downregulation of microRNAs (miRs) 29A-B1 and 34A were identified as key contributors to resistance to apoptosis in NSCLC. A biodegradable polymeric nano-gene delivery system composed of chitosan-poly-lactic-co-glycolic acid was formulated to deliver initiator CASP8 and miRs 29A-B1 and 34A. The nano-formulation efficiently encapsulated the therapeutic genes effectively internalized into NSCLC cells and induced significant apoptosis. Evaluation of the nano-formulation in A549 tumor spheroids showed a significant increase in apoptosis within the core of the spheroids, suggesting effective penetration into the spheroid structures. We provide a novel nano-formulation that demonstrate therapeutic potential for suicidal gene therapy in NSCLC.

Modified dipeptide based nanospheres as a potent adjuvating delivery system for recombinant vaccines

Recombinant protein vaccines offer an advantage without a safety risk in eliciting desired humoral and cell-mediated immune responses against infectious diseases. But one of their disadvantages is their low immunogenicity, thus requiring adjuvants that augment their immunogenicity. It is necessary to explore new technology that could provide a non-toxic, biodegradable, and biocompatible delivery system with adjuvant characteristics and nanotechnology provides an excellent platform for nanomaterial-based vaccine adjuvants. Here, we have synthesized a modified dipeptide, Arg-α, β-dehydrophenyalanine (RΔF) containing ΔF at its C-terminal, and characterized it using reversed-phase high-performance liquid chromatography (RP-HPLC) and mass spectrometry techniques. RΔF upon its self-assembly to spherical nanoparticles (NPs) efficiently condensed a recombinant Plasmodium falciparum surface protein, histidine-tagged MSPFu24 (Fu24H). The morphological characteristics of the nanoparticle formulation was characterized using TEM. RΔF NPs and RΔF-Fu24H complex showed excellent in vitro biocompatibility toward two mammalian cell lines and human red blood cells (RBCs). Furthermore, mice treated with R∆F NPs showed histological and haematological properties similar to the untreated control group which indicated their very high in vivo biocompatibility. Mice treated with RΔF-Fu24H nanoformulation induced a high titers of anti-Fu24H specific antibodies and showed a mixed Th1 and Th2 profile, comparable to the FDA-approved adjuvant Alhydrogel®. The sera from immunized mice inhibited the erythrocyte invasion activity of P. falciparum’s laboratory line 3D7 in vitro which was comparable to that of Alhydrogel®. The present study suggests that the highly biocompatible dipeptide-based nanoparticle formulation can further be developed and used in clinic as a promising antigen delivery platform to elicit immune responses.

Injectable Anhydrous Poly(ethylene glycol) Polymer Liquids Form Protein Depot for Extended Controlled Release Applications Via Rapid In Situ Gelation.

Water-free preparation of protein delivery systems has the potential to overcome the limitations of hydrogel depot systems such as off-target reactions, functional group hydrolysis, and limited loading capacity. However, a major roadblock in the development and use of these systems is administration as implantation is often required. In this study, we developed a biodegradable and water-free injectable protein delivery system via inverse electron demand Diels-Alder reaction between norbornene- and tetrazine-functionalized four-armed poly(ethylene glycol) macromonomers. 1:1 mixtures of these precursors gelled rapidly in situ, taking less than 11 s to reach their gelation point. Methyl substitution of tetrazine slowed the gelation time and increased the cross-linking density, whereas oxygen incorporation into norbornene changed the mechanical properties. Introduction of hydrolytically cleavable groups enabled biodegradability. Using phenyl carbamate and phenyl carbonate ester groups, we could tune the stability. Controlled release of the protein surrogate glucose oxidase was achieved over a period of 500 days. The novel preparation method presented here is a promising step toward the development of water-free injectable protein depots for controlled drug delivery.

Doxorubicin-Loaded Multivesicular Liposomes (DepoFoam) as a Sustained Release Carrier Intended for Locoregional Delivery in Cancer Treatment: Development, Characterization, and Cytotoxicity Evaluation.

Despite the advantages of direct intratumoral (IT) injection, the relatively rapid withdrawal of most anti-cancer drugs from the tumor due to their small molecular size limits the effectiveness of this method of administration. To address these limitations, recently, increasing attention has been directed to using slow-release biodegradable delivery systems for IT injection. This study aimed to develop and characterize a doxorubicin-loaded DepoFoam system as an efficient controlled-release carrier to be employed for locoregional drug delivery in cancer treatment. Major formulation parameters, including the molar ratio of cholesterol to the main lipid [Chol/egg phosphatidylcholine (EPC)], triolein (TO) content, and lipid-to-drug molar ratio (L/D), were optimized using a two-level factorial design approach. The prepared batches were evaluated for encapsulation efficiency (EE) and percentage of drug release (DR) after 6 and 72 hours as dependent variables. The optimum formulation (named DepoDOX) was further evaluated in terms of particle size, morphology, zeta potential, stability, Fourier-transform infrared spectroscopy, in vitro cytotoxicity, and hemolysis. The analysis of factorial design indicated that TO content and L/D ratio had a negative effect on EE; between these two, TO content had the greatest effect. The TO content was also the most significant component, with a negative effect on the release rate. The ratio of Chol/EPC showed a dual effect on the DR rate. Using a higher percentage of Chol slowed down the initial release phase of the drug; nevertheless, it accelerated the DR rate in the later slow phase. DepoDOX were spherical and honeycomb-like structures (≈ 9.81 μm) with a desired sustained release profile, as DR lasted 11 days. Its biocompatibility was confirmed by the results of cytotoxicity and hemolysis assays. The in vitro characterization of optimized DepoFoam formulation demonstrated its suitability for direct locoregional delivery. DepoDOX, as a biocompatible lipid-based formulation, showed appropriate particle size, high capability for encapsulating doxorubicin, superior physical stability, and a markedly prolonged DR rate. Therefore, this formulation could be considered a promising candidate for locoregional drug delivery in cancer treatment.

Fabrication of Fe(III)-doped mesoporous silica nanoparticles as biocompatible and biodegradable theranostic system for Remdesivir delivery and MRI contrast agent

Coronavirus causes the majority of common colds and is spread in the same way that all viruses attack the respiratory system. Despite the trials and efforts to produce a suitable vaccine, there are solutions for the quick, effective and efficient use of existing drugs to prevent infections and improve the condition of patients. In this study, we synthesized mSiO2 NPs doped with Fe(III) (Fe(III)-mSiO2) and loaded with Rd, and then the NPs coated with PDA as gatekeeper. The several surface methods successfully approved fabrication of the nanosystem. Finally, the application of nanosystem as theranostic system was studied. The DLS measurements showed the average sizes of 115 ± 2 and 124 ± 3.6 nm for Fe-SiO2 and Fe-SiO2@PDA NPs, respectively, suitable for theranostic intentions. The drug release experiments, the in-vitro MRI measurements and MTT test were accomplished, respectively, to show applicability of the nanosystem as a biodegradable Rd delivery system, MRI contrast agent, and the biocompatibility nanocarrier. The results achieved through in-vitro tests exhibited that the Fe-SiO2 system has potential application as a contrast agent in MRI with relaxivity (r1) of 14 ± 1 mM−1 s−1. The Rd drug was released from the Fe-SiO2(Rd)load@PDA system more efficient and faster than SiO2(Rd)load@PDA at 7.4, supporting the doping of Fe in SiO2 induces a biodegradability feature in that. The in-vitro biocompatibility studies showed that the Fe-SiO2 NPs (without drug) is not toxic.

PREFORMULATION STUDY OF CEFTRIAXONE AND CIPROFLOXACIN FOR LIPID BASED DRUG DELIVERY SYSTEMS

Several tests should be performed to rule out any potential physical or chemical interactions between the active pharmaceutical ingredient and the various excipients that might be utilized in the manufacturing of the drug formula. Fourier Transform infrared spectroscopy is a simple technique for the detection of changes within excipient-drug mixtures. In addition to speeding up the aging process of drugs and their possible interactions with excipients, isothermal stress testing was achieved. In this study, Ceftriaxone sodium (CTX), and Ciprofloxacin hydrochloride (CIPRO) as active ingredients were subjected to several tests to exclude any interaction with the excipients that could be used in the formulation of lipid base biodegradable antibiotic for prevention of post-operative infection. The compatibility was tested by using Fourier Transform infrared spectroscopy (FT-IR) and isothermal stability testing (IST). As a result, the IR spectral interpretation showed that the spectra obtained from the binary mixtures match the original spectra of API. Generally, there was no obvious and influential change of any characteristic peaks which confirms the absence of chemical interaction between the CTX or CIPRO and excipients. In the IST, the API – excipient mixture shows no significant change in physical properties. There was no change in color, gas formation, and liquefaction of the mixture stored under stress conditions. There was no significant change in the amount of API after storage in stressed conditions at statistical significance (p = 0.05). In conclusion, there are no notable interactions between API and the various excipients that could be employed to create biodegradable lipid-based delivery systems that are effective at preventing post-operative infection.

Telescopic synthesis and encapsulation of anticancer drugs from Ajuga bracteosa Wall. ex Benth. with zeolitic imidazole framework‐8

Cancer is one of the world's fastest‐emerging noncommunicable diseases and one of the major causes of death. Zeolitic imidazolate framework‐8 (ZIF‐8) is a subclass of metal–organic frameworks made up of organic linkers and inorganic nodes. Responsive nanocarriers with biocompatibility and precise drug release ability, superior stability under physiological conditions, pH responsiveness, and tunable drug release properties have emerged as prospective properties of ZIF‐8. Among the different options proposed for cancer treatment, natural products are used to find novel hits, which emerge as one of the most successful methods with no adverse effects. Here, we developed a novel nanoscale ZIF‐8 core encapsulated drugs extracted from Ajuga bracteosa extract in its frameworks through a facile and efficient strategy. ZIF‐8@ABE NPs show a sixfold improvement in instability compared with that of free ABE. It can internalize the NPs into cells and present targeted effects of inhibition of growth on the human Caucasian lung carcinoma cell line (A549) (adenocarcinoma). The sustained release behavior of ZIF‐8@ABE has shown a higher efficacy than the free ABE. We envisage that such a biocompatible and biodegradable delivery system may promote the development and translation of hybrid superstructures into smart and personalized delivery platforms, but the limitations imposed by limited loading capacities have stymied the development of innovative multifunctional drug delivery systems.

The Mucoadhesive Nanoparticle-Based Delivery System in the Development of Mucosal Vaccines.

Mucosal tissue constitutes the largest interface between the body and the external environment, regulating the entry of pathogens, particles, and molecules. Mucosal immunization is the most effective way to trigger a protective mucosal immune response. However, the majority of the currently licensed vaccines are recommended to be administered by intramuscular injection, which has obvious shortcomings, such as high production costs, low patient compliance, and lack of mucosal immune response. Strategies for eliciting mucosal and systemic immune responses are being developed, including appropriate vaccine adjuvant, delivery system, and bacterial or viral vectors. Biodegradable mucoadhesive nanoparticles (NPs) are the most promising candidate for vaccine delivery systems due to their inherent immune adjuvant property and the ability to protect the antigen from degradation, sustain the release of loaded antigen, and increase the residence time of antigen at the administration site. The current review outlined the complex structure of mucosa, the mechanism of interaction between NPs and mucosa, factors affecting the mucoadhesion of NPs, and the application of the delivery system based on mucoadhesive NPs in the field of vaccines. Moreover, this review demonstrated that the biodegradable and mucoadhesive NP-based delivery system has the potential for mucosal administration of vaccines.

Development of Biodegradable Delivery Systems Containing Novel 1,2,4-Trioxolane Based on Bacterial Polyhydroxyalkanoates

In this work, delivery systems in the form of microparticles and films containing 1,2,4-trioxolane (ozonide, OZ) based on polyhydroxyalkanoates (PHAs) were developed. Main systems’ characteristics were investigated: the particle yield, average diameter, zeta potential, surface morphology, loading capacity, and drug release profile of microparticles, as well as surface morphology and release profiles of OZ-containing films. PHA-based OZ-loaded microparticles have been found to have satisfactory size, zeta potential, and ozonide loading-release behavior. It was noted that OZ content influenced the surface morphology of obtained systems.

Release Mechanisms and Practical Percolation Threshold for Long-acting Biodegradable Implants: An Image to Simulation Study

The development of long-acting drug formulations requires efficient characterization technique as the designed 6–12 months release duration renders real-time in vitro and in vivo experiments cost and time prohibitive. Using a novel image-based release modeling method, release profiles were predicted from X-Ray Microscopy (XRM) of T0 samples. A validation study with the in vitro release test shows good prediction accuracy of the initial burst release. Through fast T0 image-based release prediction, the impact of formulation and process parameters on burst release rate was investigated. Recognizing the limitations of XRM, correlative imaging with Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) was introduced. A water stress test was designed to directly elucidate the formation of pores through polymer-drug-water interplay. Through an iterative correction method that considers poly(lactic-co-glycolic acid) (PLGA) polymer degradation, good agreement was achieved between release predictions using FIB-SEM images acquired from T0 samples and in vitro testing data. Furthermore, using image-based release simulations, a practical percolation threshold was identified that has profound influence on the implant performance. It is proposed as an important critical quality attribute for biodegradable long-acting delivery system, that needs to be investigated and quantified.

Injectable polyelectrolyte complex-nascent HAP biodegradable antibiotic delivery system for the treatment of osteomyelitis

An injectable osteoconductive polyelectrolyte complex (PEC)–hydroxyapatite (HAP) formulation capable of controlled delivery of ciprofloxacin has been developed from a novel biodegradable PEC and antibiotic loaded nascent hydroxyapatite (n-HAP) for the treatment of osteomyelitis. A single source (chitosan) derived polyelectrolytes were complexed in situ in the presence of n-HAP, pre-loaded with ciprofloxacin. The PEC-(n-HAP) nanoformulation (HPEC) was characterized by FT-IR, XRD, TGA and TEM analyses. HPEC combines functionalities of n-HAP (crystallinity and osteoconductivity) as well as PEC (biodegradable hydrophilic electrostatically bound macromolecular network) imparting better control over swelling and degradation kinetics favourable for drug release and transport of micronutrients. MTT assay and cytoskeleton staining (MG-63 cells) established cytocompatibility of HPEC. Early biomimetic mineralization of apatite was manifested under simulated physiological condition with a Ca/P of 1.23 (day 3) and 1.55 (day 6) complimented by in vitro biomineralization of MG-63 and human osteosarcoma (HOS) cells in a week (Alizarin Red S staining), which was further validated by calcium quantification. Antibacterial efficacy of HPEC has been evaluated by delivery kinetics of ciprofloxacin and by disc diffusion method against S. aureus and E. coli. The injectable system therefore possesses unique combination of functionalities: osteoconduction enriched with early biomineralization, antibacterial activity and is biodegradable; hence highly suitable for osteomyelitis treatment.

Systemic biodistribution and hepatocyte-specific gene editing with CRISPR/Cas9 using hyaluronic acid-based nanoparticles

The goal of this study was to evaluate hepatocyte-specific gene editing, via systemic administration of hyaluronic acid (HA)-based nanoparticles in naïve CD-1 mice. Using HA-poly(ethylene imine) (HA-PEI) and HA-PEI-mannose nanoparticles with differential mannose density (1X and 2X), we have evaluated systemic biodistribution and hepatocyte-specific delivery using IVIS imaging and flow cytometry. Additionally, we have investigated hepatocyte-specific delivery and transfection of CRISPR/Cas9 gene editing plasmid and eGFP gene payload to integrate at the Rosa26 locus. IVIS imaging showed uptake of HA-PEI nanoparticles primarily by the liver, and with addition of mannose at different concentrations, the nanoparticles showed increased uptake in both the liver and spleen. HA-PEI-mannose nanoparticles showed 55–65% uptake by hepatocytes, along with uptake by resident macrophage regardless of the mannose concentration. One of two gRNA targets showed 15% genome editing and obtained similar results for all three nanoparticle formulations. Cells positive for our gene payload were greatest with HA-PEI-mannose-1X nanoparticles where 16.2% of cells were GFP positive. The results were encouraging as proof of concept for the development of a non-viral biodegradable and biocompatible polymeric delivery system for gene editing specifically targeting hepatocytes upon systemic administration.

Single Micelle Vectors based on Lipid/Block Copolymer Compositions as mRNA Formulations for Efficient Cancer Immunogene Therapy.

Immunogene therapy provides a new strategy for the treatment of colorectal cancer. Compared to plasmid DNA, mRNA possesses several advantages as a therapeutic nucleic acid material and shows high potential in cancer therapy. Although efforts have been made to conquer the limited efficiency of mRNA delivery, most of the current mRNA vectors possess complex structures or compositions, which introduces additional toxicity and hinders their further clinical application. Hence, it is highly necessary to develop potent mRNA delivery systems with simple structures. Here, we report efficient mRNA delivery using the biodegradable micelle delivery system of DMP (DOTAP-mPEG-PCL). Biodegradable DMP micelles were simply prepared by the self-assembly of cationic lipid DOTAP and the diblock polymer monomethoxy poly(ethylene glycol)-poly(ε-caprolactone). With an average size of only 30 nm, we proved that these single-structured cationic micelles are highly potent in condensing and protecting mRNA molecules, with a delivery efficiency of 60.59% on C26 mouse colon cancer cells. The micelles triggered specific internalization pathways and were fully degraded in vivo. After binding with IL-22BP (interleukin-22 binding protein)-encoding mRNA, a strongly elevated IL-22BP mRNA level was detected in C26 cells. After intraperitoneal and intratumoral injection of the DMP/mIL-22BP complex, strong inhibition effects on C26 colon cancer models were observed, with high therapeutic efficiency and safety when systemically administrated. These data suggest that the DMP micelle is an advanced single-structured mRNA delivery system with high safety.