Redox-Responsive Gold Nanoparticles Coated with Hyaluronic Acid and Folic Acid for Application in Targeting Anticancer Therapy.

Methotrexate (MTX) has poor water solubility and low bioavailability, and cancer cells can become resistant to it, which limits its safe delivery to tumor sites and reduces its clinical efficacy. Herein, we developed novel redox-responsive hybrid nanoparticles (NPs) from hyaluronic acid (HA) and 3-mercaptopropionic acid (MPA)-coated gold NPs (gold@MPA NPs), which were further conjugated with folic acid (FA). The design of FA-HA-ss-gold NPs aimed at enhancing cellular uptake specifically in cancer cells using an active FA/HA dual targeting strategy for enhanced tumor eradication. MTX was successfully encapsulated into FA-HA-ss-gold NPs, with drug encapsulation efficiency (EE) as high as >98.7%. The physicochemical properties of the NPs were investigated in terms of size, surface charges, wavelength reflectance, and chemical bonds. MTX was released in a sustained manner in glutathione (GSH). The cellular uptake experiments showed effective uptake of FA-HA-ss-gold over HA-ss-gold NPs in the deep tumor. Moreover, the release studies provided strong evidence that FA-HA-ss-gold NPs serve as GSH-responsive carriers. In vitro, anti-tumor activity tests showed that FA-HA-ss-gold/MTX NPs exhibited significantly higher cytotoxic activity against both human cervical cancer (HeLa) cells and breast cancer (BT-20) cells compared to gold only and HA-ss-gold/MTX NPs while being safe for human embryonic kidney (HEK-293) cells. Therefore, this present study suggests that FA-HA-ss-gold NPs are promising active targeting hybrid nanocarriers that are stable, controllable, biocompatible, biodegradable, and with enhanced cancer cell targetability for the safe delivery of hydrophobic anticancer drugs.

Self-Signal-Triggered Drug Delivery System for Tumor Therapy Using Cancer Cell Membrane-Coated Biocompatible Mn3O4 Nanocomposites.

In anti-cancer metastasis treatment, precise drug delivery to cancer cells remains a challenge. Innovative nanocomposites are developed to tackle these issues effectively. The approach involves the creation of manganese oxide (Mn3O4) nanoparticles (NPs) and their functionalization using trisodium citrate to yield functionalized Mn3O4 NPs (F-Mn3O4 NPs), with enhanced water solubility, stability, and biocompatibility. Subsequently, the chemotherapeutic drug doxorubicin (DOX) is encapsulated with Mn3O4 NPs, resulting in DOX/Mn3O4 NPs. To achieve cell-specific targeting, These NPs are coated with HeLa cell membranes (HCM), forming HCM/DOX/Mn3O4. For further refinement, a transferrin (Tf) receptor is integrated with cracked HCM to create Tf-HCM/DOX/Mn3O4 nanocomposites (NC) with specific cell membrane targeting capabilities. The resulting Tf-HCM/DOX/Mn3O4 NC exhibits excellent drug encapsulation efficiency (97.5%) and displays triggered drug release when exposed to NIR laser irradiation in the tumor's environment (pH 5.0 and 6.5). Furthermore, these nanocomposites show resistance to macrophage uptake and demonstrate homotypic cancer cell targeting specificity, even in the presence of other tumor cells. In vitro toxicity tests show that Tf-HCM/DOX/Mn3O4 NC achieves significant anticancer activity against HeLa and BT20 cancer cells, with percentages of 76.46% and 71.36%, respectively. These results indicate the potential of Tf-HCM/DOX/Mn3O4 NC as an effective nanoplatform for chemo-photothermal therapy.

Injectable and Multifunctional Hydrogels Based on Poly(N-acryloyl glycinamide) and Alginate Derivatives for Antitumor Drug Delivery.

Chemotherapy is a conventional treatment that uses drugs to kill cancer cells; however, it may induce side effects and may be incompletely effective, leading to the risk of tumor recurrence. To address this issue, we developed novel injectable thermal/near-infrared (NIR)-responsive hydrogels to control drug release. The injectable hydrogel formulation was composed of biocompatible alginates, poly(N-acryloyl glycinamide) (PNAGA) copolymers with an upper critical solution temperature, and NIR-responsive cross-linkers containing coumarin groups, which were gelated through bioorthogonal inverse electron demand Diels-Alder reactions. The hydrogels exhibited quick gelation times (120-800 s) and high drug loading efficiencies (>90%). The hydrogels demonstrated a higher percentage of drug release at 37 °C than that at 25 °C due to the enhanced swelling behavior of temperature-responsive PNAGA moieties. Upon NIR irradiation, the hydrogels released most of the entrapped doxorubicin (DOX) (97%) owing to the cleavage of NIR-sensitive coumarin ester groups. The hydrogels displayed biocompatibility with normal cells, while induced antitumor activity toward cancer cells. DOX/hydrogels treated with NIR light inhibited tumor growth in nude mice bearing tumors. In addition, the injected hydrogels emitted red fluorescence upon excitation at a green wavelength, so that the drug delivery and hydrogel degradation in vivo could be tracked in the xenograft model.

NIR-responsive carboxymethyl-cellulose hydrogels containing thioketal-linkages for on-demand drug delivery system.

Near-infrared (NIR) light-responsive hydrogels have emerged as a highly promising strategy for effective anticancer therapy owing to the remotely controlled release of chemotherapeutic molecules with minimal invasive manner. In this study, novel NIR-responsive hydrogels were developed from reactive oxygen species (ROS)-cleavable thioketal cross-linkers which possessed terminal tetrazine groups to undergo a bio-orthogonal inverse electron demand Diels Alder click reaction with norbornene modified carboxymethyl cellulose. The hydrogels were rapidly formed under physiological conditions and generated N2 gas as a by-product, which led to the formation of porous structures within the hydrogel networks. A NIR dye, indocyanine green (ICG) and chemotherapeutic doxorubicin (DOX) were co-encapsulated in the porous network of the hydrogels. Upon NIR-irradiation, the hydrogels showed spatiotemporal release of encapsulated DOX (>96 %) owing to the cleavage of thioketal bonds by interacting with ROS generated from ICG, whereas minimal release of encapsulated DOX (<25 %) was observed in the absence of NIR-light. The in vitro cytotoxicity results revealed that the hydrogels were highly cytocompatible and did not induce any toxic effect on the HEK-293 cells. In contrast, the DOX + ICG-encapsulated hydrogels enhanced the chemotherapeutic effect and effectively inhibited the proliferation of Hela cancer cells when irradiated with NIR-light.

Facile Fabrication of NIR-Responsive Alginate/CMC Hydrogels Derived through IEDDA Click Chemistry for Photothermal-Photodynamic Anti-Tumor Therapy.

Novel chemically cross-linked hydrogels derived from carboxymethyl cellulose (CMC) and alginate (Alg) were prepared through the utilization of the norbornene (Nb)-methyl tetrazine (mTz) click reaction. The hydrogels were designed to generate reactive oxygen species (ROS) from an NIR dye, indocyanine green (ICG), for combined photothermal and photodynamic therapy (PTT/PDT). The cross-linking reaction between Nb and mTz moieties occurred via an inverse electron-demand Diels-Alder chemistry under physiological conditions avoiding the need for a catalyst. The resulting hydrogels exhibited viscoelastic properties (G' ~ 492-270 Pa) and high porosity. The hydrogels were found to be injectable with tunable mechanical characteristics. The ROS production from the ICG-encapsulated hydrogels was confirmed by DPBF assays, indicating a photodynamic effect (with NIR irradiation at 1-2 W for 5-15 min). The temperature of the ICG-loaded hydrogels also increased upon the NIR irradiation to eradicate tumor cells photothermally. In vitro cytocompatibility assessments revealed the non-toxic nature of CMC-Nb and Alg-mTz towards HEK-293 cells. Furthermore, the ICG-loaded hydrogels effectively inhibited the metabolic activity of Hela cells after NIR exposure.

Reduction-Responsive Chitosan-Based Injectable Hydrogels for Enhanced Anticancer Therapy.

Selective delivery of anticancer drug molecules to the tumor site enhances local drug dosages, which leads to the death of cancer cells while simultaneously minimizing the negative effects of chemotherapy on other tissues, thereby improving the patient's quality of life. To address this need, we developed reduction-responsive chitosan-based injectable hydrogels via the inverse electron demand Diels-Alder reaction between tetrazine groups of disulfide-based cross-linkers and norbornene groups of chitosan derivatives, which were applied to the controlled delivery of doxorubicin (DOX). The swelling ratio, gelation time (90-500 s), mechanical strength (G'~350-850 Pa), network morphology, and drug-loading efficiency (≥92%) of developed hydrogels were investigated. The in vitro release studies of the DOX-loaded hydrogels were performed at pH 7.4 and 5.0 with and without DTT (10 mM). The biocompatibility of pure hydrogel and the in vitro anticancer activity of DOX-loaded hydrogels were demonstrated via MTT assay on HEK-293 and HT-29 cancer cell lines, respectively.

Redox-Responsive Comparison of Diselenide and Disulfide Core-Cross-Linked Micelles for Drug Delivery Application.

In this study, diselenide (Se-Se) and disulfide (S-S) redox-responsive core-cross-linked (CCL) micelles were synthesized using poly(ethylene oxide)2k-b-poly(furfuryl methacrylate)1.5k (PEO2k-b-PFMA1.5k), and their redox sensitivity was compared. A single electron transfer-living radical polymerization technique was used to prepare PEO2k-b-PFMA1.5k from FMA monomers and PEO2k-Br initiators. An anti-cancer drug, doxorubicin (DOX), was incorporated into PFMA hydrophobic parts of the polymeric micelles, which were then cross-linked with maleimide cross-linkers, 1,6-bis(maleimide) hexane, dithiobis(maleimido) ethane and diselenobis(maleimido) ethane via Diels-Alder reaction. Under physiological conditions, the structural stability of both S-S and Se-Se CCL micelles was maintained; however, treatments with 10 mM GSH induced redox-responsive de-cross-linking of S-S and Se-Se bonds. In contrast, the S-S bond was intact in the presence of 100 mM H2O2, while the Se-Se bond underwent de-crosslinking upon the treatment. DLS studies revealed that the size and PDI of (PEO2k-b-PFMA1.5k-Se)2 micelles varied more significantly in response to changes in the redox environment than (PEO2k-b-PFMA1.5k-S)2 micelles. In vitro release studies showed that the developed micelles had a lower drug release rate at pH 7.4, whereas a higher release was observed at pH 5.0 (tumor environment). The micelles were non-toxic against HEK-293 normal cells, which revealed that they could be safe for use. Nevertheless, DOX-loaded S-S/Se-Se CCL micelles exhibited potent cytotoxicity against BT-20 cancer cells. Based on these results, the (PEO2k-b-PFMA1.5k-Se)2 micelles can be more sensitive drug carriers than (PEO2k-b-PFMA1.5k-S)2 micelles.

Redox-Responsive Core-Cross-Linked Micelles of Miktoarm Poly(ethylene oxide)-b-poly(furfuryl methacrylate) for Anticancer Drug Delivery.

The physiological instability of nanocarriers, premature drug leakage during blood circulation, and associated severe side effects cause compromised therapeutic efficacy, which have significantly hampered the progress of nanomedicines. The cross-linking of nanocarriers while keeping the effectiveness of their degradation at the targeted site to release the drug has emerged as a potent strategy to overcome these flaws. Herein, we have designed novel (poly(ethylene oxide))2-b-poly(furfuryl methacrylate) ((PEO2K)2-b-PFMAnk) miktoarm amphiphilic block copolymers by coupling alkyne-functionalized PEO (PEO2K-C≡H) and diazide-functionalized poly(furfuryl methacrylate) ((N3)2-PFMAnk) via click chemistry. (PEO2K)2-b-PFMAnk self-assembled to form nanosized micelles (mikUCL) with hydrodynamic radii in the range of 25∼33 nm. The hydrophobic core of mikUCL was cross-linked by a disulfide-containing cross-linker using the Diels-Alder reaction to avoid unwanted leakage and burst release of a payload. As expected, the resulting core-cross-linked (PEO2K)2-b-PFMAnk micelles (mikCCL) exhibited superior stability under a normal physiological environment and were de-cross-linked to rapidly release doxorubicin (DOX) upon exposure to a reduction environment. The micelles were compatible with HEK-293 normal cells, while DOX-loaded micelles (mikUCL/DOX and mikCCL/DOX) induced high antitumor activity in HeLa and HT-29 cells. mikCCL/DOX preferentially accumulated at the tumor site and was more efficacious than free DOX and mikUCL/DOX for tumor inhibition in HT-29 tumor-bearing nude mice.

NIR-degradable and biocompatible hydrogels derived from hyaluronic acid and coumarin for drug delivery and bio-imaging.

In this work, bioorthogonal and photodegradable hydrogels derived from norbornene (Nb) functionalized hyaluronic acid and a water soluble coumarin-based cross-linker possessing terminal tetrazine (Tz) groups, were developed for NIR-responsive release of doxorubicin (DOX). The inverse electron demand Diels-Alder cross-linking reaction between Nb and Tz functionalities formed the hydrogels at physiological conditions, whereas N2 gas liberated during the reaction created pores in the hydrogels. The gelation time ranges (about 5-20 min) and the viscoelastic behavior (G' ~ 346-1380 Pa) demonstrated that the resulting hydrogels were injectable and possessed tunable mechanical properties. Moreover, hydrogels released the encapsulated DOX upon NIR irradiation, owing to the NIR-responsive cleavage of coumarin-ester, and consequently, induced anti-tumor activity in BT-20 cancer cells. Additionally, the hydrogels could be excited at various wavelengths of the visible spectrum and can emit green to red fluorescence, demonstrating their simultaneous photo-responsive drug release and bio-imaging applications.

Anti-Osteoarthritic Effects of Cartilage-Derived Extracellular Matrix in a Rat Osteoarthritis Model.

BACKGROUND: The extracellular matrix (ECM) has many functions, such as segregating tissues, providing support, and regulating intercellular communication. Cartilage-derived ECM (CECM) can be prepared via consecutive processes of chemical decellularization and enzyme treatment. The purpose of this study was to improve and treat osteoarthritis (OA) using porcine knee articular CECM. METHODS: We assessed the rheological characteristics and pH of CECM solutions. Furthermore, we determined the effects of CECM on cell proliferation and cytotoxicity in the chondrocytes of New Zealand rabbits. The inhibitory effect of CECM on tumor necrosis factor (TNF)-α-induced cellular apoptosis was assessed using New Zealand rabbit chondrocytes and human synoviocytes. Finally, we examined the in vivo effects of CECM on inflammation control and cartilage degradation in an experimental OA-induced rat model. The rat model of OA was established by injecting monosodium iodoacetate into the intra-articular knee joint. The rats were then injected with CECM solution. Inflammation control and cartilage degradation were assessed by measuring the serum levels of proinflammatory cytokines and C-telopeptide of type II collagen and performing a histomorphological analysis. RESULTS: CECM was found to be biocompatible and non-immunogenic, and could improve cell proliferation without inducing a toxic reaction. CECM significantly reduced cellular apoptosis due to TNF-α, significantly improved the survival of cells in inflammatory environments, and exerted anti-inflammatory effects. CONCLUSION: Our findings suggest that CECM is an appropriate injectable material that mediates OA-induced inflammation.

Reduction-responsive and bioorthogonal carboxymethyl cellulose based soft hydrogels cross-linked via IEDDA click chemistry for cancer therapy application.

In this work, novel biocompatible and reduction-responsive soft hydrogels were formulated from norbornene (Nb)-functionalized carboxymethyl cellulose (CMCNb). To cross-link the CMC-Nb via a highly bioorthogonal inverse electron demand Diels-Alder (IEDDA) reaction, we employed a water-soluble and reduction-responsive diselenide-based cross-linker possessing two terminal tetrazine (Tz) groups with varying molar concentrations (Nb/Tz molar ratios of 10/10, 10/05, and 10/2.5). The N2 microbubbles liberated as a by-product during the IEDDA reaction generated in-situ pores in hydrogel networks. The resulting hydrogels had highly porous structures and relatively soft mechanical properties (storage moduli in the range 74 ⁓160 Pa). The hydrogels showed high swelling ratios (>35 times), tunable gelation times (1-5 min), and excellent doxorubicin (DOX) loading efficiencies (>85 %). The hydrogels exhibited stimuli-responsive and fast release of DOX (99 %, after 12 h) in the presence of 10 mmol of glutathione as compared to the normal PBS solution (38 %). The cytotoxic effects of blank hydrogels were not observed against HEK-239 cells, while the DOX-encapsulated hydrogels exhibited anti-tumor activity in BT-20 cancer cells. The results indicate potential applications of the CMC-based soft hydrogels in injectable drug delivery systems.

Human Fetal Cartilage-Derived Progenitor Cells Exhibit Anti-Inflammatory Effect on IL-1ß-Mediated Osteoarthritis Phenotypes In Vitro.

BACKGROUND: In this study, we have investigated whether human fetal cartilage progenitor cells (hFCPCs) have anti-inflammatory activity and can alleviate osteoarthritis (OA) phenotypes in vitro. METHODS: hFCPCs were stimulated with various cytokines and their combinations and expression of paracrine factors was examined to find an optimal priming factor. Human chondrocytes or SW982 synoviocytes were treated with interleukin-1ß (IL-1ß) to produce OA phenotype, and co-cultured with polyinosinic-polycytidylic acid (poly(I-C))-primed hFCPCs to address their anti-inflammatory effect by measuring the expression of OA-related genes. The effect of poly(I-C) on the surface marker expression and differentiation of hFCPCs into 3 mesodermal lineages was also examined. RESULTS: Among the priming factors tested, poly(I-C) (1 µg/mL) most significantly induced the expression of paracrine factors such as indoleamine 2,3-dioxygenase, histocompatibility antigen, class I, G, tumor necrosis factor- stimulated gene-6, leukemia inhibitory factor, transforming growth factor-ß1 and hepatocyte growth factor from hFCPCs. In the OA model in vitro, co-treatment of poly(I-C)-primed hFCPCs significantly alleviated IL-1ß-induced expression of inflammatory factors such as IL-6, monocyte chemoattractant protein-1 and IL-1ß, and matrix metalloproteinases in SW982, while it increased the expression of cartilage extracellular matrix such as aggrecan and collagen type II in human chondrocytes. We also found that treatment of poly(I-C) did not cause significant changes in the surface marker profile of hFCPCs, while showed some changes in the 3 lineages differentiation. CONCLUSION: These results suggest that poly(I-C)-primed hFCPCs have an ability to modulate inflammatory response and OA phenotypes in vitro and encourage further studies to apply them in animal models of OA in the future.

The Progress of Stem Cell Therapy in Myocardial-Infarcted Heart Regeneration: Cell Sheet Technology.

Various tissues, including the heart, cornea, bone, esophagus, bladder and liver, have been vascularized using the cell sheet technique. It overcomes the limitations of existing techniques by allowing small layers of the cell sheet to generate capillaries on their own, and it can also be used to vascularize tissue-engineered transplants. Cell sheets eliminate the need for traditional tissue engineering procedures such as isolated cell injections and scaffold-based technologies, which have limited applicability. While cell sheet engineering can eliminate many of the drawbacks, there are still a few challenges that need to be addressed. The number of cell sheets that can be layered without triggering core ischemia or hypoxia is limited. Even when scaffold-based technologies are disregarded, strategies to tackle this problem remain a substantial impediment to the efficient regeneration of thick, living three-dimensional cell sheets. In this review, we summarize the cell sheet technology in myocardial infarcted tissue regeneration.

Multi-stimuli responsive hydrogels derived from hyaluronic acid for cancer therapy application.

One of the most promising strategies for the controlled release of therapeutic molecules is stimuli-responsive and biodegradable hydrogels developed from natural polymers. However, current strategies to development stimuli-responsive hydrogels lack precise control over drug release profile and use cytotoxic materials during preparation. To address these issues, multi-stimuli responsive hydrogels derived from hyaluronic acid and diselenide based cross-linker were developed for the controlled release of doxorubicin (DOX). Hydrogels were rapidly formed via an inverse electron demand Diels-Alder click chemistry and encapsulated DOX/indocyanine green (ICG) in their porous networks. The hydrogels showed a rapid release of DOX in acidic (pH 5), reducing (10 mmol DTT), and oxidizing medium (0.5% H2O2), and after NIR irradiation. The in vitro experiments demonstrated that hydrogels were highly cytocompatible and the DOX-loaded hydrogels induced similar anti-tumor effect as compared to that of the free-DOX. Furthermore, DOX + ICG loaded hydrogels increased the antitumor efficacy of DOX after NIR irradiation.

Effects of Induction Culture on Osteogenesis of Scaffold-Free Engineered Tissue for Bone Regeneration Applications.

BACKGROUND: Restoration of the bone defects caused by infection or disease remains a challenge in orthopedic surgery. In recent studies, scaffold-free engineered tissue with a self-secreted extracellular matrix has been proposed as an alternative strategy for tissue regeneration and reconstruction. Our study aimed to engineer and fabricate self-assembled osteogenic and scaffold-free tissue for bone regeneration. METHODS: Osteogenic scaffold-free tissue was engineered and fabricated using fetal cartilage-derived progenitor cells, which are capable of osteogenic differentiation. They were cultured in osteogenic induction environments or using demineralized bone powder for differentiation. The fabricated tissue was subjected to real-time qPCR, biochemical, and histological analyses to estimate the degree of in vitro osteogenic differentiation. To demonstrate bone formation in an in vivo environment, scaffold-free tissue was transplanted into the dorsal subcutaneous site of nude mice. Bone development was monitored postoperatively over 8 weeks by the observation of calcium deposition in the matrix. RESULTS: In the in vitro experiments, engineered osteogenically induced scaffold-free tissue demonstrated three-dimensional morphological characteristics, and sufficient osteogenic differentiation was confirmed through the quantification of specific osteogenic gene markers expressed and calcium accumulation within the matrix. Following the evaluation of differentiation efficacy, in vivo experiments revealed distinct bone formation, and that blood vessels had penetrated the fabricated tissue. CONCLUSION: The novel engineering of scaffold-free tissue with osteogenic potential can be used as an optimal bone graft substitute for bone regeneration.

Injectable and biocompatible alginate-derived porous hydrogels cross-linked by IEDDA click chemistry for reduction-responsive drug release application.

In this work, novel injectable and reduction-responsive hydrogels were successfully prepared via inverse electron demand Diels-Alder reaction between alginate-norbornene and a water-soluble PEG based disulfide cross-linker. The reduction-responsive cross-linker was designed to contain a PEG chain within two disulfide linkages, and two terminal tetrazine groups. The resulting hydrogels possessed high swelling ratios, porous morphology, excellent drug loading efficiency (~92%), and suitable mechanical properties. The drug release experiments demonstrated that the hydrogels released more than 90% of the encapsulated doxorubicin (DOX) in the presence of 10 mM glutathione while a minimal DOX release (<25%) was measured in physiological buffer (PBS, pH = 7.4) after 11 d. The cross-linker and hydrogels did not exhibit any apparent cytotoxicity to fibroblast cells. In contrast, DOX-loaded hydrogels induced anti-tumor activity against cancer cells. The injectable and reduction-responsive hydrogels hold great potential as a biomaterial for stimuli responsive drug delivery applications.

A phlorotannins-loaded homogeneous acellular matrix film modulates post-implantation inflammatory responses.

Peritendinous adhesion mainly occurs between proliferating fibrous tissues and adjacent normal organs after surgery. Many physical barriers are applied to the implanted site to prevent peritendinous adhesion. However, these barriers often trigger inflammatory responses. Therefore, our study sought to develop phlorotannins-loaded cartilage acellular matrix (CAM) films as a physical barrier and investigate their inhibitory effect on inflammatory responses, which are associated with the induction of postoperative peritendinous adhesion (PAA). Our findings indicated that incorporating phlorotannin into the CAM film did not affect its unique characteristics including its thermal and spectroscopic properties. Moreover, the phlorotannins-loaded CAM films suppressed the expression of inflammatory mediators on RAW 264.7 macrophages stimulated using Escherichia coli lipopolysaccharides and exhibited an anti-inflammatory effect when implanted subcutaneously in rats. Therefore, our results highlight the potential of phlorotannins-loaded CAM films as a promising physical barrier to prevent PAA.

Near-Infrared Light-Responsive Shell-Crosslinked Micelles of Poly(d,l-lactide)-b-poly((furfuryl methacrylate)-co-(N-acryloylmorpholine)) Prepared by Diels-Alder Reaction for the Triggered Release of Doxorubicin.

In the present study, we developed near-infrared (NIR)-responsive shell-crosslinked (SCL) micelles using the Diels-Alder (DA) click reaction between an amphiphilic copolymer poly(d,l-lactide)20-b-poly((furfuryl methacrylate)10-co-(N-acryloylmorpholine)78) (PLA20-b-P(FMA10-co-NAM78)) and a diselenide-containing crosslinker, bis(maleimidoethyl) 3,3'-diselanediyldipropionoate (BMEDSeDP). The PLA20-b-P(FMA10-co-NAM78) copolymer was synthesized by RAFT polymerization of FMA and NAM using a PLA20-macro-chain transfer agent (PLA20-CTA). The DA reaction between BMEDSeDP and the furfuryl moieties in the copolymeric micelles in water resulted in the formation of SCL micelles. The SCL micelles were analyzed by 1H-NMR, FE-SEM, and DLS. An anticancer drug, doxorubicin (DOX), and an NIR sensitizer, indocyanine green (ICG), were effectively incorporated into the SCL micelles during the crosslinking reaction. The DOX/ICG-loaded SCL micelles showed pH- and NIR-responsive drug release, where burst release was observed under NIR laser irradiation. The in vitro cytotoxicity analysis demonstrated that the SCL was not cytotoxic against normal HFF-1 cells, while DOX/ICG-loaded SCL micelles exhibited significant antitumor activity toward HeLa cells. Thus, the SCL micelles of PLA20-b-P(FMA10-co-NAM78) can be used as a potential delivery vehicle for the controlled drug release in cancer therapy.

Characterization of Marine Organism Extracellular Matrix-Anchored Extracellular Vesicles and Their Biological Effect on the Alleviation of Pro-Inflammatory Cytokines.

Representative marine materials such as biopolymers and bioceramics contain bioactive properties and are applied in regenerative medicine and tissue engineering. The marine organism-derived extracellular matrix (ECM), which consists of structural and functional molecules, has been studied as a biomaterial. It has been used to reconstruct tissues and improve biological functions. However, research on marine-derived extracellular vesicles (EVs) among marine functional materials is limited. Recent studies on marine-derived EVs were limited to eco-system studies using bacteria-released EVs. We aimed to expand the range of representative marine organisms such as fish, crustaceans, and echinoderms; establish the extraction process; and study the bioactivity capability of marine EVs. Results confirmed that marine organism ECM-anchored EVs (mEVs) have a similar morphology and cargos to those of EVs in land animals. To investigate physiological effects, lipopolysaccharide (LPS)-infected macrophages were treated with EVs derived from sea cucumber, fish, and shrimp. A comparison of the expression levels of inflammatory cytokine genes revealed that all types of mEVs alleviated pro-inflammatory cytokines, although to different degrees. Among them, the sea cucumber-derived EVs showed the strongest suppression ability. This study showed that research on EVs derived from various types of marine animals can lead to the development of high value-added therapeutics from discarded marine wastes.

Onlay-graft of 3D printed Kagome-structure PCL scaffold incorporated with rhBMP-2 based on hyaluronic acid hydrogel.

The onlay-graft, one of the most difficult graft conditions, is used for diverse clinical conditions, including plastic and dental surgery. The graft should withstand continuous pressure from overlying tissues and have excellent bone formation capability in a limited bone contact situation. We recently developed a 3D printed Kagome-structured polycaprolactone (PCL) scaffold that has a stronger mechanical property. This study evaluated the clinical feasibility of this scaffold for onlay-graft use. The value of the scaffold containing recombinant human bone morphogenetic protein-2 in a hyaluronate-based hydrogel (rhBMP-2/HA) to enhance bone regeneration was also assessed. 3D-printed Kagome-PCL scaffolds alone (n= 12, group I) or loaded with rhBMP-2/HA (n= 12, group II) were grafted using a rat calvarial onlay-graft model. Following sacrifice at 2, 4, and 8 weeks, all 3D-printed Kagome-PCL scaffolds were accurately positioned and firmly integrated to the recipient bone. Micro-computed tomography and histology analyses revealed a constant height of the scaffolds over time in all animals. New bone grew into the scaffolds in both groups, but with greater volume in group II. These results suggest the promising clinical feasibility of the 3D-printed Kagome-PCL scaffold for onlay-graft use and it could substitute the conventional onlay-graft in the plastic and dental reconstructive surgery in the near future.