Engineering of targeting antioxidant polypeptide nanopolyplexes for the treatment of acute lung injury.

The pathogenesis of acute lung injury (ALI) involves various mechanisms, such as oxidative stress, inflammation, and epithelial cell apoptosis. However, current drug therapies face limitations due to issues like systemic distribution, drug degradation in vivo, and hydrophobicity. To address these challenges, we developed a pH-responsive nano-drug delivery system for delivering antioxidant peptides to treat ALI. In this study, we utilized low molecular weight chitosan (LMWC) and hyaluronic acid (HA) as carrier materials. LMWC carries a positive charge, while HA carries a negative charge. By stirring the two together, the electrostatic adsorption between LMWC and HA yielded aggregated drug carriers. To specifically target the antioxidant drug WNWAD to lung lesions and enhance therapeutic outcomes for ALI, we created a targeted drug delivery system known as HA/LMWC@WNWAD (NPs) through a 12-h stirring process. In our research, we characterized the particle size and drug release of NPs. Additionally, we assessed the targeting ability of NPs. Lastly, we evaluated the improvement of lung injury at the cellular and animal levels to investigate the therapeutic mechanism of this drug targeting delivery system.

Engineering of VCAM-1-targeted nanostructured lipid carriers for delivery of melatonin against acute lung injury through SIRT1/NLRP3 mediated pyroptosis signaling pathway.

Acute lung injury (ALI) is a prevalent and critical condition in clinical practice. Although certain pharmacological interventions have demonstrated benefits in preclinical studies, none have been proven entirely effective thus far. Therefore, the development of more efficient treatment strategies for ALI is imperative. In this study, we prepared nanostructured lipid carriers (NLCs) conjugated with anti-VCAM-1 antibodies to encapsulate melatonin (MLT), resulting in VCAM/MLT NLCs. This approach aimed to enhance the distribution of melatonin in lung vascular endothelial cells. The VCAM/MLT NLCs had an average diameter of 364 nm, high drug loading content, and a sustained drug release profile. Notably, the NLCs conjugated with anti-VCAM-1 antibodies demonstrated more specific cellular delivery mediated by the VCAM-1 receptors, increased cellular internalization, and enhanced accumulation in lung tissues. Treatment with VCAM/MLT NLCs effectively alleviated pulmonary inflammation by activating NLRP3 inflammasome-dependent pyroptosis through up-regulation of Sirtuin 1. Our findings suggest that VCAM/MLT NLCs demonstrate remarkable therapeutic effects on ALI in both in vitro and in vivo settings, making them a promising and efficient treatment strategy for ALI.

Targeted-lung delivery of bardoxolone methyl using PECAM-1 antibody-conjugated nanostructure lipid carriers for the treatment of lung inflammation.

The effective treatment of acute lung injury (ALI) remains a significant challenge. Patients with ALI demonstrate an abundance of proinflammatory mediators in both bronchoalveolar lavage fluid (BALF) and circulating plasma. Bardoxolone methyl (BM) is a semi-synthetic triterpenoid derived from oleanolic acid, a natural product known for its ability to inhibit proinflammatory signaling. GSDMD is a signaling protein involved in pyroptosis, a form of programmed cell death. It has been reported that its upstream proteins play a role in the pathogenesis of ALI. However, there is currently no research examining whether the effect of BM on the occurrence and development of ALI is associated with changes in GSDMD protein. In this study, we prepared nanostructured lipid carriers loaded with BM and conjugated with anti-PECAM-1 antibody (PECAM@BM NLCs). PECAM@BM NLCs were designed to specifically bind to pulmonary vascular endothelial cells that highly express the PECAM-1 receptors. We also aimed to investigate the protective effects of PECAM@BM NLCs on ALI and elucidate the underlying molecular mechanisms. The results demonstrated that PECAM@BM NLCs accumulated in the lung tissues and significantly alleviated the inflammatory injury of ALI. This was evidenced by the changes in the lung wet/dry ratio, the total protein concentration, proinflammatory cytokines in BALF, and the histopathological progress. Additionally, we elucidated that PECAM@BM NLCs had the ability to inhibit the assembly of NLRP3 inflammasome and pro-caspase-1 complex, thereby suppressing the induction of pyroptosis. This mechanism resulted in the inhibition of N-terminal GSDMD expression and effectively prevented the progression of ALI.

Correction: An E-selectin targeting and MMP-2-responsive dextran-curcumin polymeric prodrug for targeted therapy of acute kidney injury.

Correction for 'An E-selectin targeting and MMP-2-responsive dextran-curcumin polymeric prodrug for targeted therapy of acute kidney injury' by Jing-Bo Hu et al., Biomater. Sci., 2018, 6, 3397-3409, https://doi.org/10.1039/C8BM00813B.

Corrigendum: Advances in the research of nano delivery systems in ischemic stroke.

[This corrects the article DOI: 10.3389/fbioe.2022.984424.].

A Stepwise Targeting Curcumin Derivative, Ser@TPP@CUR, for Acute Kidney Injury.

Based on the pathological mechanisms of acute kidney injury (AKI), a stepwise targeting curcumin derivative, Ser@TPP@CUR, was developed in this study. Ser@TPP@CUR can be specifically internalized by renal tubular epithelial cells via KIM-1 receptor-mediated endocytosis and then actively distributed in mitochondria under the effect of TPP, a mitochondrial targeting molecule. Both in vitro and in vivo results showed that Ser@TPP@CUR effectively ameliorated injured renal tubular epithelial cells and improved renal functions of AKI mice.

Correction to "A Stepwise Targeting Curcumin Derivative, Ser@TPP@CUR, for Acute Kidney Injury".

[This corrects the article DOI: 10.1021/acsmedchemlett.1c00585.].

Advances in the research of nano delivery systems in ischemic stroke.

Ischemic stroke is the most common type of cerebrovascular disease with high disability rate and mortality. The blood-brain barrier (BBB) protects the homeostasis of the brain's microenvironment and impedes the penetration of 98% of drugs. Therefore, effective treatment requires the better drug transport across membranes and increased drug distribution. Nanoparticles are a good choice for drugs to cross BBB. The main pathways of nano delivery systems through BBB include passive diffusion, adsorption-mediated endocytosis, receptor-mediated transport, carrier-mediated transport, etc. At present, the materials used in brain-targeted delivery can be divided into natural polymer, synthetic polymers, inorganic materials and phospholipid. In this review, we first introduced several ways of nano delivery systems crossing the BBB, and then summarized their applications in ischemic stroke. Based on their potential and challenges in the treatment of ischemic stroke, new ideas and prospects are proposed for designing feasible and effective nano delivery systems.

Targeting pulmonary vascular endothelial cells for the treatment of respiratory diseases.

Pulmonary vascular endothelial cells (VECs) are the main damaged cells in the pathogenesis of various respiratory diseases and they mediate the development and regulation of the diseases. Effective intervention targeting pulmonary VECs is of great significance for the treatment of respiratory diseases. A variety of cell markers are expressed on the surface of VECs, some of which can be specifically combined with the drugs or carriers modified by corresponding ligands such as ICAM-1, PECAM-1, and P-selectin, to achieve effective delivery of drugs in lung tissues. In addition, the great endothelial surface area of the pulmonary vessels, the "first pass effect" of venous blood in lung tissues, and the high volume and relatively slow blood perfusion rate of pulmonary capillaries further promote the drug distribution in lung tissues. This review summarizes the representative markers at the onset of respiratory diseases, drug delivery systems designed to target these markers and their therapeutic effects.

Engineering of stepwise-targeting chitosan oligosaccharide conjugate for the treatment of acute kidney injury.

Acute kidney injury (AKI) is a common and serious clinical syndrome of acute renal dysfunction in a short period. One of therapeutic interventions for AKI is to reduce ROS massively generated in the mitochondria and then ameliorate cell damage and apoptosis induced by oxidative stress. In this study, stepwise-targeting chitosan oligosaccharide, triphenyl phosphine-low molecular weight chitosan-curcumin (TPP-LMWC-CUR, TLC), was constructed for sepsis-induced AKI via removing excessive ROS in renal tubular epithelial cells. Benefiting from good water solubility and low molecular weight, TLC was rapidly and preferentially distributed in the renal tissues and then specifically internalized by tubular epithelium cells via interaction between Megalin receptor and LMWC. The intracellular TLC could further delivery CUR to mitochondria due to high buffering capacity of LMWC and delocalized positive charges of TPP. Both in vitro and in vivo pharmacodynamic results demonstrated the enhanced therapeutic effect of TLC in the treatment of AKI.

Preparation of Ethyl Cellulose Microspheres for Sustained Release of Sodium Bicarbonate.

Sustained release of thermal-instable and water-soluble drugs with low molecule weight is a challenge. In this study, sodium bicarbonate was encapsulated in ethyl cellulose microspheres by a novel solid-in-oil-in-oil (S/O/O) emulsification method using acetonitrile/soybean oil as new solvent pairs. Properties of the microspheres such as size, recovery rate, morphology, drug content, and drug release behavior were evaluated to investigate the suitable preparation techniques. In the case of that the ratio of the internal and external oil phase was 1: 9, Tween 80 as a stabilizer resulted in the highest drug content (2.68%) and a good spherical shape of microspheres. After the ratio increased to 1: 4, the microspheres using Tween 80 as the stabilizer also had high drug content (1.96%) and exhibited a sustained release behavior, with 70% of drug released within 12 h and a sustained release of more than 40 h. Otherwise, different emulsification temperatures at which acetonitrile was evaporated could influence the drug release behaviour of microspheres obtained. This novel method is a potential and effective method to achieve the encapsulation and the sustained release of thermal-instable and water-soluble drugs with low molecule weight.

Polycaprolactone/polysialic acid hybrid, multifunctional nanofiber scaffolds for treatment of spinal cord injury.

Scaffold-based tissue engineering is widely used for spinal cord injury (SCI) treatment by creating supporting and guiding neuronal tissue regeneration. However, how to enhance the axonal regeneration capacity following SCI still remains a challenge. Polysialic acid (PSA), a natural, biodegradable polysaccharide, has been increasingly explored for controlling central nervous system (CNS) development by regulating cell adhesive properties and promoting axonal growth. Here, a polycaprolactone (PCL)/PSA hybrid nanofiber scaffold encapsulating glucocorticoid methylprednisolone (MP) is developed for SCI treatment. Rat models with spinal cord transection is established and the PCL/PSA/MP scaffold is transplanted into lesion area. PCL/PSA/MP scaffold decreases tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) release by inhibiting ionized calcium-binding adapter molecule 1 (Iba1) positive microglia/macrophage activation and reduces apoptosis-associated Caspase-3 protein expression. In addition, the PCL/PSA/MP scaffold inhibits axonal demyelination and glial fibrillary acidic protein (GFAP) expression, increases neurofilament 200 (NF-200) expression and improves functional outcome by Basso, Beattie and Bresnahan (BBB) test. These results demonstrate the therapeutic potential of PSA hybrid nanofiber scaffold in promoting axonal growth and enhancing the functional recovery following SCI. STATEMENT OF SIGNIFICANCE: Scaffold-based tissue engineering is widely used for spinal cord injury (SCI) treatment by creating supporting and guiding neuronal tissue regeneration. And how to enhance the axonal regeneration capacity following SCI still remains a challenge. Polysialic acid (PSA), a natural, biodegradable polysaccharide, has been increasingly explored for controlling central nervous system (CNS) development by regulating cell adhesive properties and promoting axonal growth. However, in vivo therapeutic effect of PSA scaffolds towards SCI is still lack of evidence and needs to be further explored. In this study, a novel electrospun polycaprolactone/PSA scaffold loaded with methylprednisolone (MP) was developed to achieve efficient therapeutic effects towards SCI. And we believe that it broadens the application of PSA for SCI treatment.

Endogenous sialic acid-engineered micelles: a multifunctional platform for on-demand methotrexate delivery and bone repair of rheumatoid arthritis.

Rheumatoid arthritis (RA) patients have suffered from the current drug therapeutic regimen because of its high toxicity and the absence of bone regeneration for existing erosion, seriously affecting the quality of life. Herein, a sialic acid-dextran-octadecanoic acid (SA-Dex-OA) conjugate was synthesized to form micelles with a 55.06 µg mL-1 critical micelle concentration. The obtained micelles can encapsulate a disease-modifying anti-rheumatic drug, methotrexate (MTX), with 4.28% (w/w) drug content, featuring sustained drug release behavior over 48 h. In vitro and in vivo studies showed that SA-Dex-OA micelles significantly improved accumulation and transportation through a combination of SA and E-selectin receptors in inflamed cells and arthritic paws highly expressing E-selectin. MTX-loaded SA-Dex-OA micelles not only significantly inhibited the inflammatory response, but also diminished the adverse effects of MTX, as reflected by the reduced alanine aminotransferase, aspartate aminotransferase, creatinine, and urea nitrogen levels. Most importantly, the bone mineral density in rats treated with MTX-loaded SA-Dex-OA micelles was significantly higher as compared to in those treated with free MTX and Dex-OA/MTX micelles (increasing from 391.4 to 417.4 to 492.7 mg cc-1), benefiting from the effects of endogenous sialic acid in promoting MC3T3-E1 cell differentiation and mineralization. It is anticipated that SA-based micelles with bone repair activities have great potential for RA treatment and other metabolic bone diseases with serious bone erosion.

An E-selectin targeting and MMP-2-responsive dextran-curcumin polymeric prodrug for targeted therapy of acute kidney injury.

Based on the overproduction of matrix metalloproteinase-2 (MMP-2) in renal tissue during acute kidney injury (AKI) occurrence, we developed a MMP-2 enzyme-triggered polymeric prodrug with sialic acid (SA) as the targeting group to the inflamed vascular endothelial cells for enhanced therapeutic outcomes. An MMP-2-responsive peptide, PVGLIG, was used to endow the polymeric prodrug with the ability to rapidly release the anti-inflammatory drug, curcumin (CUR), after the targeted site is reached and to improve the drug concentration in the target tissue. The sialic acid-dextran-PVGLIG-curcumin (SA-DEX-PVGLIG-CUR) polymeric prodrug was successfully synthesized via multi-step chemical reactions and characterized by 1H NMR. The water solubility of CUR was significantly increased in the polymeric prodrug and was approximately 23-fold higher than that of free CUR. The in vitro drug release results showed that the release rate of SA-DEX-PVGLIG-CUR was significantly enhanced compared to that of SA-DEX-CUR in a dissolving medium containing the MMP-2 enzyme, suggesting that SA-DEX-PVGLIG-CUR had rapid drug release characteristics in an inflammatory environment. A cellular uptake test confirmed that SA-DEX-PVGLIG-CUR was effectively internalized by inflamed vascular endothelial cells in comparison with that by normal cells, and the mechanism was associated with the specific interaction between SA and E-selectin receptors specifically expressed on inflamed vascular endothelial cells. Bio-distribution results further demonstrated the rapid and increased renal accumulation of SA-DEX-PVGLIG-CUR in AKI mice. Benefiting from the rapid drug release in renal tissue, SA-DEX-PVGLIG-CUR effectively ameliorated the pathological progression of AKI compared with free CUR and SA-DEX-CUR, as reflected by the improved renal functions, histopathological changes, pro-inflammatory cytokine production, oxidative stress and expression of apoptosis related proteins. Altogether, this study provided a new therapeutic strategy for the treatment of AKI.

CD44-targeted hyaluronic acid-curcumin prodrug protects renal tubular epithelial cell survival from oxidative stress damage.

Based on the abnormally increased expression of CD44 receptors on renal tubule epithelial cells during ischemia/reperfusion-induced acute kidney injury (AKI), we developed a hyaluronic acid-curcumin (HA-CUR) polymeric prodrug targeting to epithelial cells and then relieving oxidative stress damages. The water solubility of HA-CUR was significantly enhanced and approximately 27-fold higher than that of CUR. Cellular uptake test showed HA-CUR was preferably internalized by H2O2-pretreated tubular epithelial (HK-2) cells compared with free CUR benefiting from the specific binding between HA and CD44 receptors. Biodistribution results further demonstrated the increased accumulation of HA-CUR in kidneys with 13.9-fold higher than that of free CUR. Pharmacodynamic studies indicated HA-CUR effectively ameliorated AKI, and the exact mechanism was that HA-CUR protected renal tubule epithelial cells from oxidative stress damage via inhibiting PtdIns3K-AKT-mTOR signaling pathway. Taken together, this study provides a new therapeutic strategy for the treatment of AKI based on the pathogenesis of the disease.

Targeting delivery of simvastatin using ICAM-1 antibody-conjugated nanostructured lipid carriers for acute lung injury therapy.

Acute lung injury (ALI) is a critical illness without effective therapeutic modalities currently. Recent studies indicated potential efficacy of statins for ALI, while high-dose statins was suggested to be significant for attenuating inflammation in vivo. Therefore, a lung-targeted drug delivery system (DDS) delivering simvastatin (SV) for ALI therapy was developed, attempting to improve the disease with a decreased dose and minimize potential adverse effects. SV-loaded nanostructured lipid carriers (SV/NLCs) with different size were prepared primarily. With particle size increasing from 143.7 nm to 337.8 nm, SV/NLCs showed increasing drug-encapsulated efficiency from 66.70% to 91.04%. Although larger SV/NLCs exhibited slower in vitro cellular uptake by human vascular endothelial cell line EAhy926 at initial stage, while in vivo distribution demonstrated higher pulmonary accumulation of the larger ones. Thus, the largest size SV/NLCs (337.8 nm) were conjugated with intercellular adhesion molecule 1 (ICAM-1) antibody (anti-ICAM/SV/NLCs) for lung-targeted study. The anti-ICAM/SV/NLCs exhibited ideal lung-targeted characteristic in lipopolysaccharide-induced ALI mice. In vivo i.v. administration of anti-ICAM/SV/NLCs attenuated TNF-α, IL-6 and inflammatory cells infiltration more effectively than free SV or non-targeted SV/NLCs after 48-h administration. Significant histological improvements by anti-ICAM/SV/NLCs were further revealed by H&E stain. Therefore, ICAM-1 antibody-conjugated NLCs may represent a potential lung-targeted DDS contributing to ALI therapy by statins.

E-selectin-targeted Sialic Acid-PEG-dexamethasone Micelles for Enhanced Anti-Inflammatory Efficacy for Acute Kidney Injury.

The effective treatment for acute kidney injury (AKI) is currently limited, and care is primarily supportive. Sialic acid (SA) is main component of Sialyl Lewisx antigen on the mammalian cell surface, which participates in E-selectin binding. Therefore, dexamethasone(DXM)-loaded E-selectin-targeting sialic acid-polyethylene glycol-dexamethasone (SA-PEG-DXM/DXM) conjugate micelles are designed for ameliorating AKI. The conjugates are synthesized via the esterification reaction between PEG and SA or DXM, and can spontaneously form micelles in an aqueous solution with a 65.6 µg/mL critical micelle concentration. Free DXM is incorporated into the micelles with 6.28 ± 0.21% drug loading content. In vitro DXM release from SA-PEG-DXM/DXM micelles can be prolonged to 48h. Much more SA-PEG-DXM micelles can be internalized by lipopolysaccharide (LPS)-activated human umbilical vein endothelial cells (HUVECs) in comparison to PEG-DXM micelles due to specific interaction between SA and E-selectin expressed on HUVECs, and consequently more SA-PEG-DXM micelles are accumulated in the kidney of AKI murine model. Furthermore, SA in SA-PEG-DXM conjugates can significantly ameliorate LPS-induced production of pro-inflammatory cytokines via suppressing LPS-activated Beclin-1/Atg5-Atg12-mediated autophagy to attenuate toxicity. Compared with free DXM and PEG-DXM/DXM micelles, SA-PEG-DXM/DXM micelles show better therapeutical effects, as reflected by the improved renal function, histopathological changes, pro-inflammatory cytokines, oxidative stress and expression of apoptotic related proteins.

Mild microwave activated, chemo-thermal combinational tumor therapy based on a targeted, thermal-sensitive and magnetic micelle.

The development of combinational anti-tumor therapy is of great value. Here, the thermal-sensitive and hepatic tumor cell targeting peptide-A54 modified polymer, A54-poly(ethylene glycol)-g-poly(acrylamide-co-acrylonitrile) (A54-PEG-g-p(AAm-co-AN)) can self-assemble into an 80 nm-sized micelle, which shows a thermal-sensitive behavior with an upper critical solution temperature (UCST) of 43 °C. This self-assembled and targeted A54-PEG-g-p(AAm-co-AN) micelle can co-encapsulate anti-tumor drug doxorubicin (DOX) and magnetic nanoparticles (MNPs) taking advantage of the hydrophobic core of the core-shell micellar structure, when the temperature is lower than 43 °C. A much higher accumulation of the MNPs@A54-PEG-g-p(AAm-co-AN) to the tumor navigated by the A54 targeting peptide is achieved. Due to the thermal-agent effect of the accumulated MNPs in tumor, the mild microwave (8 W) applied afterwards specifically elevates the local tumor temperature by 13 °C, compared to 6 °C without MNPs accumulation in 30 min. The greater temperature rise resulted from the thermal-agent effect of MNPs doesn't only activate the drug release inside tumor cells, but also achieve an augmented hyperthermia. A mild microwave activated, chemo-thermal combinational tumor therapy is thus developed.

T2-Weighted Magnetic Resonance Imaging of Hepatic Tumor Guided by SPIO-Loaded Nanostructured Lipid Carriers and Ferritin Reporter Genes.

Nowadays, there is a high demand for supersensitive contrast agents for the early diagnostics of hepatocarcinoma. It has been recognized that accurate imaging information is able to be achieved by constructing hepatic tumor specific targeting probes, though it still faces challenges. Here, a AGKGTPSLETTP peptide (A54)-functionalized superparamagnetic iron oxide (SPIO)-loaded nanostructured lipid carrier (A54-SNLC), which can be specifically uptaken by hepatoma carcinoma cell (Bel-7402) and exhibited ultralow imaging signal intensity with varied Fe concentration on T2-weighted imaging (T2WI), was first prepared as an effective gene carrier. Then, an endogenous ferritin reporter gene for magnetic resonance imaging (MRI) with tumor-specific promoter (AFP-promoter) was designed, which can also exhibit a decrease in signal intensity on T2WI. At last, using protamine as a cationic mediator, novel ternary nanoparticle of A54-SNLC/protamine/DNA (A54-SNPD) as an active dual-target T2-weighted MRI contrast agent for imaging hepatic tumor was achieved. Owing to the synergistic effect of A54-SNLC and AFP-promoted DNA targeting with Bel-7402 cells, T2 imaging intensity values of hepatic tumors were successfully decreased via the T2 contrast enhancement of ternary nanoparticles. It is emphasized that the novel A54-SNPD ternary nanoparticle as active dual-target T2-weighted MRI contrast agent were able to greatly increase the diagnostic sensitivity and specificity of hepatic cancer.