Photoresponsive metal-organic framework with combined photodynamic therapy and hypoxia-activated chemotherapy for the targeted treatment of rheumatoid arthritis.

Activated M1-type macrophages, which produce inflammatory factors that exacerbate rheumatoid arthritis (RA), represent crucial target cells for inhibiting the disease process. In this study, we developed a novel photoresponsive targeted drug delivery system (TPNPs-HA) that can effectively deliver the hypoxia-activated prodrug tirapazamine (TPZ) specifically to activated macrophages. After administration, this metal-organic framework, PCN-224, constructed uing the photosensitizer porphyrin, exhibits the ability to generate excessive toxic reactive oxygen species (ROS) when exposed to near-infrared light. Additionally, the oxygen-consumed hypoxic environment further activates the chemotherapeutic effect of TPZ, thus creating a synergistic combination of photodynamic therapy (PDT) and hypoxia-activated chemotherapy (HaCT) to promote the elimination of activated M1-type macrophages. The results highlight the significantly potential of this photoresponsive nano-delivery system in providing substantial relief for RA. Furthermore, these findings support its effectiveness in inhibiting the disease process of RA, thereby offering new possibilities for the development of precise and accurate strategies for RA.

Targeting and Microenvironment-Activated Nanoreactor for Diabetic Chronic Wound Healing via Multienzyme Cascade Reactions.

The development of cell-like nanoreactors with the ability to initiate biocatalytic cascades under special conditions holds tremendous potential for therapeutic applications. Herein, conformationally gated nanoreactors that respond to the acidic microenvironment of infected diabetic wounds were developed by cucur[8]bituril (CB[8])-based supramolecular assembly. The bioinspired nanoreactors exhibit not only self-regulated permeability and selectivity to control internal enzyme activities by substance exchange but also distinct binding specificities toward Gram-positive and Gram-negative bacteria via noncovalent modification with different ligands. The encapsulation of glucose oxidase (GOx), Fe3O4 nanozyme, and l-arginine (l-Arg) into the nanocarriers enables intelligent activation of multienzyme cascade reactions upon glucose (Glu) uptake to produce gluconic acid (GA) and hydrogen peroxide (H2O2), which is further converted into highly toxic hydroxyl radicals (·OH) for selective antibacterial activity. Moreover, acidic H2O2 promotes the oxidization of l-Arg, leading to the release of nitric oxide (NO). Consequently, this nanoreactor provides a multifunctional and synergistic platform for diabetic chronic wound healing by combining enzyme dynamic therapy with NO gas therapy to combat bacterial infections and inflammation under high blood Glu levels.

Applications and Research Advances in the Delivery of CRISPR/Cas9 Systems for the Treatment of Inherited Diseases.

The rapid advancements in gene therapy have opened up new possibilities for treating genetic disorders, including Duchenne muscular dystrophy, thalassemia, cystic fibrosis, hemophilia, and familial hypercholesterolemia. The utilization of the clustered, regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) system has revolutionized the field of gene therapy by enabling precise targeting of genes. In recent years, CRISPR/Cas9 has demonstrated remarkable efficacy in treating cancer and genetic diseases. However, the susceptibility of nucleic acid drugs to degradation by nucleic acid endonucleases necessitates the development of functional vectors capable of protecting the nucleic acids from enzymatic degradation while ensuring safety and effectiveness. This review explores the biomedical potential of non-viral vector-based CRISPR/Cas9 systems for treating genetic diseases. Furthermore, it provides a comprehensive overview of recent advances in viral and non-viral vector-based gene therapy for genetic disorders, including preclinical and clinical study insights. Additionally, the review analyzes the current limitations of these delivery systems and proposes avenues for developing novel nano-delivery platforms.

Multifunctional nanoadjuvant-driven microenvironment modulation for enhanced photothermal immunotherapy in breast cancer.

Intracellular redox imbalance, achieved by exploiting the tumor microenvironment (TME), has emerged as a promising strategy for cancer therapy. In this study, we developed a multifunctional nanoadjuvant, termed GITFe/Z-HA, by modified a metal-organic backbone Fe/ZIF-8 with hyaluronic acid (HA) targeting. The nanocarriers were loaded with glucose oxidase (Gox), neoindocyanine green (IR820) and tilazamine (TPZ). This design aimed to achieve a cascade reaction within tumor cells, mediated by Gox, Fe3+, and IR820, which consumes intrinsic glucose and oxygen, leading to an elevated production of reactive oxygen species (ROS). This cascade reaction creates a hypoxic environment conducive for TPZ to exert its therapeutic action. Consequently, the combination of photothermal therapy (PTT), photodynamic therapy (PDT), and chemotherapy demonstrates a good synergistic effect. Moreover, the imbalanced ROS/glutathione (GSH) induced by this treatment approach, along with PTT, promote immunogenic cell death (ICD). This ICD triggers the release of damage-related molecular patterns and CD8+ lymphocyte infiltration sensitizes the immune checkpoint blockade (αPD-L1) response, thereby eliciting a systemic anti-tumor immune response. Collectively, this comprehensive treatment regimen, driven by environmentally stimulated multiple pathways, overcomes the limitations of single therapeutic modalities, thereby improving tumor outcomes. Additionally, these findings provide valuable insights for strategies aimed at modulating the tumor immune microenvironment.

Multi-Enzyme Cascade-Triggered Nitric Oxide Release Nanoplatform Combined with Chemo Starvation-like Therapy for Multidrug-Resistant Cancers.

Tumor drug resistance has long been a major challenge in medical oncology. Ferroptosis is a form of regulated cell death with promising clinical applications. However, the efficacy of ferroptosis-inducing agents is often limited by endogenous factors when used alone, and thus, synergistic therapy offers a promising strategy to address this issue. In this study, we developed an iron-doped metal-organic framework (MOF), Fe/ZIF-8, loaded with glucose oxidase (Gox), l-arginine (l-arg), and adriamycin hydrochloride (Dox). The folic acid (FA)-targeted ZIF-8 (GLDFe/Z-FA) prepared was shown to be a multifunctional nanoparticle based on endogenous hydrogen peroxide (H2O2) and glucose, which trigger adaptive cellular responses in cancer cells. The intracellular glucose level and adenosine-triphosphate (ATP) content decreased, indicating that GLDFe/Z-FA reduced the glucose metabolic rate and induced tumor starvation. And the generated •OH and H2O2 induced reactive oxygen species (ROS) overload to implement chemodynamic therapy (CDT). ROS catalyzed l-arg released from GLDFe/Z-FA to release nitric oxide (NO), which inhibited P-glycoprotein expression, prevented Dox efflux, and accumulated intracellular content of Dox to enhance cytotoxicity. GLDFe/Z-FA also catalyzed glutathione degradation, which further disrupted intracellular redox homeostasis, enhanced CDT, and induced cell death. It was shown to follow the ferroptosis pathway and strongly inhibited tumor proliferation both in vitro and in vivo. These findings demonstrate that GLDFe/Z-FA effectively inhibits tumor proliferation, highlighting its potential as a viable therapeutic approach to suppress cancer progression.

Influence of Er:YAG laser irradiation on the outcomes of alveolar ridge preservation at the infected molar sites: a randomized controlled trial.

BACKGROUND: The purpose of this study was to investigate the socket healing outcome after alveolar ridge preservation at infected molar sites using an erbium-doped yttrium aluminium garnet (Er:YAG) laser. METHODS: Eighteen patients who needed molar extraction and exhibited signs of infection were included and allocated into either the laser group or the control group. Er:YAG laser irradiation for degranulation and disinfection was performed with alveolar ridge preservation (ARP) in the laser group. Traditional debridement with a curette was performed in the control group. Two months after ARP, bone tissue samples were harvested at the time of implant placement for histological analysis. Assessment of dimension changes in alveolar bone was conducted by superimposing two cone-beam computed tomography (CBCT) scans taken at baseline and two months after extraction. RESULTS: Histologically, after two months of healing, Er:YAG laser treatment resulted in more newly formed bone (laser: 17.75 ± 8.75, control: 12.52 ± 4.99, p = 0.232). Moreover, greater osteocalcin (OCN) positive expression and lower runt-related transcription factor 2 (RUNX-2) positive expression were detected in the laser group. However, no statistically significant difference was observed between the two groups. The difference in the vertical resorption of the buccal bone plate was statistically significant between groups (laser: -0.31 ± 0.26 mm, control: -0.97 ± 0.32 mm, p < 0.05). Major changes in ridge width were observed at 1 mm below the bone crest. However, the differences between groups were not significant (laser: -0.36 ± 0.31 mm, control: -1.14 ± 1.24 mm, p = 0.171). CONCLUSIONS: ARP with Er:YAG laser irradiation seemed to improve bone healing by regulating osteogenesis-related factor expression in the early stage at infected sites. TRIAL REGISTRATION: The trial was registered on the Chinese Clinical Trial Registry Platform ( https://www.chictr.org.cn/ ) (registration number: ChiCTR2300068671; registration date: 27/02/2023).

A Multifunctional Nano-Delivery System Against Rheumatoid Arthritis by Combined Phototherapy, Hypoxia-Activated Chemotherapy, and RNA Interference.

Purpose: Effective therapy for rheumatoid arthritis (RA) keeps a challenge due to the complex pathogenesis of RA. It is not enough to completely inhibit the process of RA with any single therapy method. The purpose of the research is to compensate for the insufficiency of monotherapy using multiple treatment regimens with different mechanisms. Material and Methods: In this study, we developed a new method to synthesize mesoporous silica nanoparticles hybridized with photosensitizer PCPDTBT (HNs). Branched polyethyleneimine-folic acid (PEI-FA) could be coated on the surface of HNs through electrostatic interactions. It simultaneously blocked the hypoxia-activated prodrug tirapazamine loaded into the mesopores and binded with Mcl-1 siRNA (siMcl-1) that interfered with the expression of the anti-apoptotic protein Mcl-1. Released from the co-delivery nanoparticles (PFHNs/TM) Tirapazamine and siMcl-1 upon exposure to acidic conditions of endosomes/lysosomes in activated macrophages. Under NIR irradiation, photothermal therapy and photodynamic therapy derived from PCPDTBT, hypoxia-activated chemotherapy derived from tirapazamine, and RNAi derived from siMcl-1 were used for the combined treatment for RA by killing activated macrophages. PEI-FA-coated PFHNs/TM exhibited activated macrophage-targeting characteristics, thereby enhancing the in vitro and in vivo NIR-induced combined treatment of RA. Results: The prepared PFHNs/TM have high blood compatibility (far below 5% of hemolysis) and ideal in vitro phototherapy effect while controlling the TPZ release and binding siMcl-1. We prove that PEI-FA-coated PFHNs/TM not only protect the bound siRNA but also are selectively uptaked by activated macrophages through FA receptor-ligand-mediated endocytosis, and effectively silence the target anti-apoptotic protein by siMcl-1 transfection. In vivo, PFHNs/TM have also been revealed to be selectively enriched at the inflammatory site of RA, exhibiting NIR-induced anti-RA efficacy. Conclusion: Overall, these FA-functionalized, pH-responsive PFHNs/TM represent a promising platform for the co-delivery of chemical drugs and nucleic acids for the treatment of RA cooperating with NIR-induced phototherapy.

Nano-Based Co-Delivery System for Treatment of Rheumatoid Arthritis.

A systemic autoimmune condition known as rheumatoid arthritis (RA) has a significant impact on patients' quality of life. Given the complexity of RA's biology, no single treatment can totally block the disease's progression. The combined use of co-delivery regimens integrating various diverse mechanisms has been widely acknowledged as a way to make up for the drawbacks of single therapy. These days, co-delivery systems have been frequently utilized for co-treatment, getting over drug limitations, imaging of inflammatory areas, and inducing reactions. Various small molecules, nucleic acid drugs, and enzyme-like agents intended for co-delivery are frequently capable of producing the ability to require positive outcomes. In addition, the excellent response effect of phototherapeutic agents has led to their frequent use for delivery together with chemotherapeutics. In this review, we discuss different types of nano-based co-delivery systems and their advantages, limitations, and future directions. In addition, we review the prospects and predicted challenges for the combining of phototherapeutic agents with conventional drugs, hoping to provide some theoretical support for future in-depth studies of nano-based co-delivery systems and phototherapeutic agents.

A nanotherapy responsive to the inflammatory microenvironment for the dual-targeted treatment of atherosclerosis.

Atherosclerosis remains the main cause of death and disability, as well as a leading cause of coronary arterial disease. Inflammation is one of the pathogenic factors of arteriosclerosis; however, the current treatments based on lowering the level of inflammation in the plaque tissue of patients with atherosclerosis are not clinically used. Herein, we hypothesize that αvß3 receptor affinity and low pH sensitivity may be regarded as a valid therapeutic strategy for targeting sites of atherosclerosis according to the microenvironments of inflammation. To prove this tentative hypothesis, an acid-labile material polyketal named PK3 was synthesized, and the cRGDfc peptide was used to modify nanoparticles composed of poly(lactide-co-glycolide) (PLGA), lecithin, and PK3, loaded with the anti-atherosclerotic drug rapamycin (RAP). The nanoparticles were prepared using an O/W method and then characterized, which showed an appropriate particle size and fulfilling responsive behaviors. In vitro release studies and stability tests showed that these nanoparticles can be effectively internalized by human umbilical vein endothelial cells (HUVEC), and also show a good in vitro anti-inflammatory effect. After intravenous (i.v.) injection, RGD targeted by pH-responsive nanotherapy (RAP-Nps-RGD) may be accumulated at the plaque site in ApoE-/- mice with atherosclerosis and can effectively attenuate plaque progression compared to other formulations. Moreover, its good safety profile and biocompatibility have been revealed in both in vitro and in vivo estimations. Accordingly, the prospect of nanoparticles responsive to the inflammatory microenvironment for preventing atherosclerotic through inflammation modulation provides great feasibility for the administration of alternate drug molecules to inflamed sites to slow down the process of arteriosclerosis.

Near-infrared triggered ropivacaine liposomal gel for adjustable and prolonged local anaesthesia.

Local analgesics effectively allow patients to relieve postoperative pain and reduce the need for inhaled general anesthetics or opioids. Compared with other similar long-acting local anesthetics, ropivacaine (Rop) is widely used due to its potential to minimize cardiotoxicity. However, the relatively short duration of Rop efficacy, which lasts for several hours after injection, is considered insufficient for long-term acute and chronic pain treatment. At present, repeated injections or indwelling catheters are used to achieve long-term drug delivery, which can easily cause infection and inflammation. To achieve externally controllable analgesia for a prolonged time, we prepared near-infrared (NIR)-responsive Rop liposomes (Rop@Lip) containing photosensitizers PdPC(OBu)8 and unsaturated phospholipid DLPC. The particle size of the Rop@Lip was 234.73 ± 5.21 nm, the PDI was 0.42 ± 0.02, and the drug encapsulation rate was 94.62 ± 1.1%. The release of Rop was highly NIR-dependent in vitro and in vivo. To ensure that the liposomes reside around the nerve for an extended period, we next designed an in situ gel with chitosan (CS) and ß-sodium glycerophosphate (ß-GP) to form a liposomal gel (Lip/Gel). This Lip/Gel composite drug delivery system could be retained in vivo for 10 d, reduce the side effects caused by drug overdose, and prolong the duration of efficacy. In summary, the NIR-responsive Rop composite drug delivery system generated in this paper can effectively solve the shortcomings of traditional local injections, reduce the toxicity and side effects of free Rop, and provide a basis for a light-responsive delivery system of analgesic drugs.

Nanotechnology for Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a degenerative eye disease that is the leading cause of irreversible vision loss in people 50 years and older. Today, the most common treatment for AMD involves repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF) drugs. However, the existing expensive therapies not only cannot cure this disease, they also produce a variety of side effects. For example, the number of injections increases the cumulative risk of endophthalmitis and other complications. Today, a single intravitreal injection of gene therapy products can greatly reduce the burden of treatment and improve visual effects. In addition, the latest innovations in nanotherapy provide the best drug delivery alternative for the treatment of AMD. In this review, we discuss the development of nano-drug delivery systems and gene therapy strategies for AMD in recent years. In addition, we discuss some novel targeting strategies and the potential application of these delivery methods in the treatment of AMD. Finally, we also propose that the combination of CRISPR/Cas9 technology with a new non-viral delivery system may be promising as a therapeutic strategy for the treatment of AMD.

Folate receptor-targeting semiconducting polymer dots hybrid mesoporous silica nanoparticles against rheumatoid arthritis through synergistic photothermal therapy, photodynamic therapy, and chemotherapy.

With ideal optical properties, semiconducting polymer quantum dots (SPs) have become a research focus in recent years; a considerable number of studies have been devoted to the application of SPs in non-invasive and biosafety phototherapy with near-infrared (NIR) lasers. Nevertheless, the relatively poor stability of SPs in vitro and in vivo remains problematic. PCPDTBT was chosen to synthesize photothermal therapy (PTT) and photodynamic therapy (PDT) dual-model SPs, considering its low band gap and desirable absorption in the NIR window. For the first time, cetrimonium bromide was used as a stabilizer to guarantee the in vitro stability of SPs, and as a template to prepare SP hybrid mesoporous silica nanoparticles (SMs) to achieve long-term stability in vivo. The mesoporous structure of SMs was used as a reservoir for the hypoxia-activated prodrug Tirapazamine (TPZ). SMs were decorated with polyethylene glycol-folic acid (SMPFs) to specifically target activated macrophages in rheumatoid arthritis (RA). Upon an 808 nm NIR irradiation, the SMPFs generate intracellular hyperthermia and excessive singlet oxygen. Local hypoxia caused by molecular oxygen consumption simultaneously activates the cytotoxicity of TPZ, which effectively kills activated macrophages and inhibits the progression of arthritis. This triple PTT-PDT-chemo synergistic treatment suggests that SMPFs realize the in vivo application of SPs and may be a potential nano-vehicle for RA therapy with negligible side-toxicity.

Optomechanical Design and Application of Solar-Skylight Spectroradiometer.

Using a solar radiometer is an effective approach for improving the remote sensing of solar irradiance distribution and atmospheric composition. Long-term development of a solar scanning radiometer enables frequent and reliable measurement of atmospheric parameters such as the water vapor column and aerosol optical properties. However, the discrete wavelength radiometer has encountered a bottleneck with respect to its insufficient spectral resolution and limited observation waveband, and it has been unable to satisfy the needs of refined and intelligent on-site experiments. This study proposes a solar-skylight spectroradiometer for obtaining visible and near-IR fine spectrum with two types of measurement: direct-sun irradiance and diffuse-sky radiance. The instrument adopts distributed control architecture composed of the ARM-Linux embedded platform and sensor networks. The detailed design of the measuring light-path, two-axis turntable, and master control system will be addressed in this study. To determine all coefficients needed to convert instrument outputs to physical quantities, integrating sphere and Langley extrapolation methods are introduced for diffuse-sky and direct-sun calibration, respectively. Finally, the agreement of experimental results between spectroradiometers and measuring benchmarks (DTF sun-photometer, microwave radiometer, and Combined Atmospheric Radiative Transfer simulation) verifies the feasibility of the spectroradiometer system, and the radiation information of feature wavelengths can be used to retrieve the characteristics of atmospheric optics.

Self-Assembled pH-Sensitive Polymeric Nanoparticles for the Inflammation-Targeted Delivery of Cu/Zn-Superoxide Dismutase.

The use of superoxide dismutase (SOD) is currently limited by its short half-life, rapid plasma clearance rate, and instability. We synthesized a small library of biofriendly amphiphilic polymers that comprise methoxy poly(ethylene glycol)-poly(cyclohexane-1,4-diyl acetone dimethyleneketal) (mPEG-PCADK) and mPEG-poly((cyclohexane86.7%, 1,5-pentanediol13.3%)-1,4-diyl acetone dimethylene ketal) (PK3) for the targeted delivery of SOD. The novel polymers could self-assemble into micellar nanoparticles with favorable hydrolysis kinetics, biocompatibility, long circulation time, and inflammation-targeting effects. These materials generated a better pH-response curve and exhibited better hydrolytic kinetic behavior than PCADK and PK3. The polymers showed good biocompatibility with protein drugs and did not induce an acidic microenvironment during degradation in contrast to materials such as PEG-block-poly(lactic-co-glycolic acid) (PLGA) and PLGA. The SOD that contained reverse micelles based on mPEG2000-PCADK exhibited good circulation and inflammation-targeting properties. Pharmacodynamic results indicated exceptional antioxidant and anti-inflammatory activities in a rat adjuvant-induced arthritis model and a rat peritonitis model. These results suggest that these copolymers are ideal protein carriers for targeting inflammation treatment.

Polyketal Nanoparticles Co-Loaded With miR-124 and Ketoprofen for Treatment of Rheumatoid Arthritis.

Ketoprofen, a non-steroidal anti-inflammatory drug, can effectively relieve pain associated with arthritis, and microRNA-124 (miR-124) can inhibit the progression of the disease. In this study, poly (cyclohexane-1,4-diylacetone dimethylene ketal) (PCADK) nanoparticles (NPs) co-loaded with ketoprofen and miR-124 were successfully prepared using an emulsified solvent evaporation method. The co-loaded NPs exhibited a mean particle diameter of 160 nm. The acid sensitivity of the NPs was determined through in vitro release experiments. An adjuvant-induced arthritis rat model of arthritis was established for evaluating the pharmacodynamics of the NPs through clinical scoring and degree of swelling. The PCADK NPs exhibited more potent pharmacodynamic effects owing to the acid-sensitive properties of the carrier materials, compared with Poly (lactic-co-glycolic acid) (PLGA) NPs. Furthermore, PCADK co-loaded NPs exhibited superior anti-inflammatory effects compared to NPs loaded with either miR-124 or ketoprofen alone. In conclusion, co-delivery of ketoprofen and miR-124 through NPs is a promising strategy for the treatment of arthritis.

PLGA/PCADK composite microspheres containing hyaluronic acid-chitosan siRNA nanoparticles: A rational design for rheumatoid arthritis therapy.

Myeloid cell leukemia-1 (Mcl-1), a member of the Bcl-2 anti-apoptotic family, is overexpressed in the synovial macrophages of patients with rheumatoid arthritis (RA). Small interfering RNA (siRNA) Mcl-1 can induce macrophage apoptosis in the joints and is a potential therapeutic target of RA. Nevertheless, the application of siRNA is limited owing to its instability and susceptibility to degradation in vivo. To address these shortcomings, we developed composite microspheres (MPs) loaded with hyaluronic acid (HA)-chitosan (CS) nanoparticles (NPs). First, we synthesized HA-CS/siRNA NPs (HCNPs) using ionotropic gelation process. Then, HCNPs, as an internal aqueous phase, were loaded into poly (D, L-lactide-co-glycolide) (PLGA) and poly (cyclohexane-1,4-diyl acetone dimethylene ketal) (PCADK) MPs using the double emulsion method. The NPs-in-MPs (NiMPs) composite system provided sustained release of NPs, protected siRNA against nuclease degradation in the serum, and could readily cross the cellular membrane. In addition, we evaluated the advantages of NiMPs in an adjuvant-induced arthritis rat model. Our experimental results demonstrate that NiMPs have greater pharmacodynamic effects than common MPs. Meanwhile, compared with HCNPs, NiMPs reduced the frequency of drug administration. Therefore, NiMPs are a promising and novel siRNA delivery vehicle for RA therapy.

Folate receptor-targeting mesoporous silica-coated gold nanorod nanoparticles for the synergistic photothermal therapy and chemotherapy of rheumatoid arthritis.

The synergy of photothermal therapy (PTT) and chemotherapy is widely regarded as an effective treatment for complex diseases, such as cancer and inflammation. In this paper, we report the synthesis of a nanoscaled drug delivery system, which was composed of a gold nanorod (GNR) as the photothermal agent and a mesoporous silica shell as the methotrexate (MTX) reservoir, named FAGMs. Due to folate modification on the surface, FAGMs targeted specifically activated macrophages in rheumatoid arthritis (RA). Under 808 nm laser irradiation, FAGMs could kill macrophages by reaching sufficient local hyperthermia with excellent efficiency in the photothermal conversion of GNRs. Meanwhile, internal heating caused hydrogen bond fracture; thus, MTX released rapidly from FAGMs for localized synergistic PTT and chemotherapy. The FAGMs had a mean particle size of about 180 nm and a zeta potential of 14.36 mV. The release rate of MTX from FAGMs in vitro increased markedly under 808 nm laser irradiation. In a cellular uptake study, stronger fluorescence signals were observed in activated macrophages when treated with FAGMs, suggesting that folic acid molecules enabled the enhancement of endocytosis into activated macrophages. In rats with adjuvant-induced arthritis, synergistic treatment excellently inhibited the progression of RA. These results demonstrated that FAGMs could be promising for the treatment of RA.

Synthesis and Biological Application of Polylactic Acid.

Over the past few decades, with the development of science and technology, the field of biomedicine has rapidly developed, especially with respect to biomedical materials. Low toxicity and good biocompatibility have always been key targets in the development and application of biomedical materials. As a degradable and environmentally friendly polymer, polylactic acid, also known as polylactide, is favored by researchers and has been used as a commercial material in various studies. Lactic acid, as a synthetic raw material of polylactic acid, can only be obtained by sugar fermentation. Good biocompatibility and biodegradability have led it to be approved by the U.S. Food and Drug Administration (FDA) as a biomedical material. Polylactic acid has good physical properties, and its modification can optimize its properties to a certain extent. Polylactic acid blocks and blends play significant roles in drug delivery, implants, and tissue engineering to great effect. This article describes the synthesis of polylactic acid (PLA) and its raw materials, physical properties, degradation, modification, and applications in the field of biomedicine. It aims to contribute to the important knowledge and development of PLA in biomedical applications.

Cyclic RGD Peptide Targeting Coated Nano Drug Co-Delivery System for Therapeutic Use in Age-Related Macular Degeneration Disease.

Vascular endothelial growth factor (VEGF) expression increased significantly in the pathogenesis of age-related macular degeneration, which induced the formation of pathological blood vessels. Dexamethasone is an exogenous anti-angiogenic drug while bevacizumab is an endogenous anti-angiogenic drug. They both have been widely used in ophthalmology. However, independent administration is not enough to completely block the development of choroidal neovascularization (CNV), and the number of eyes vitreous injections is limited. Reasonable combination of drugs may produce significantly better therapeutic effect than single drug treatment. The cyclic RGD (cRGD) peptide has a particularly high affinity with retinal pigment epithelial cells, where VEGF secretes from. In this study, we prepared nanoparticles of bevacizumab and dexamethasone with cRGD peptide as the target (aBev/cRGD-DPPNs). The particle size of the aBev/cRGD-DPPNs was 213.8 ± 1.5 nm, SEM results showed that the nano-carriers were well dispersed and spherical. The cell uptake study demonstrated the selectivity of the aBev/cRGD-DPPN to ARPE-19 with αVß3 over expressed. The aBev/cRGD-DPPNs had a better apoptosis induction effect and an obvious inhibitory effect on migration, invasion, and capillary-like structures formation of human umbilical vein epithelial cells. The fluorescein fundus angiography study, immunohistochemistry and histopathological evaluation showed the aBev/cRGD-DPPNs greatly reduced the development of CNV on a rabbit model.

Study of double-targeting nanoparticles loaded with MCL-1 siRNA and dexamethasone for adjuvant-induced arthritis therapy.

The co-delivery of nanoparticles encapsulating gene therapies and chemotherapeutic drugs can achieve synergistic treatment and reduce side effects in normal tissues relative to the systemic use of single drug delivery. Activated macrophages play a fundamental role in the pathogenesis of rheumatoid arthritis (RA). Hyaluronic acid (HA), a natural polysaccharide, is a specific ligand for CD44 that is overexpressed on the surface of activated macrophages. In this study, HA-coated pH-responsive nanoparticles loaded with MCL-1 small interfering RNA (siRNA) and dexamethasone (HNPs/MD) were developed for RA treatment. The HNPs/MD had a mean particle size of 117.07 ± 2.21 nm and zeta potential of 15.53 ± 1.06 mV. The release rates of both MCL-1 siRNA and dexamethasone from the HNPs/MD at pH 4.5 and 6.0 were higher than those at pH 7.4, indicating that the nanoparticles were acid-sensitive. Cytotoxicity assays showed that compared with single drug loaded nanoparticles, the HNPs/MD showed higher cytotoxicity to activated macrophages. The superior therapeutic effect of HNPs/MD was demonstrated in an adjuvant-induced arthritis rat model. These findings indicate that pH-sensitive and HA-targeting co-delivery nanoparticles provide a new direction for the therapy of RA.