Mussel Inspired Trigger-Detachable Adhesive Hydrogel.

Adhesion to many kinds of surfaces, including biological tissues, is important in many fields but has been proved to be extremely challenging. Furthermore, peeling from strong adhesion is needed in many conditions, but is sometimes painful. Herein, a mussel inspired hydrogel is developed to achieve both strong adhesion and trigger-detachment. The former is actualized by electrostatic interactions, covalent bonds, and physical interpenetration, while the latter is triggered, on-demand, through combining a thixotropic supramolecular network and polymer double network. The results of the experiments show that the hydrogel can adhere to various material surfaces and tissues. Moreover, triggered by shear force, non-covalent interactions of the supramolecular network are destroyed. This adhesion can be peeled easily. The possible mechanism involved is discussed and proved. This work will bring new insight into electronic engineering and tissue repair like skin care for premature infants and burn victims.

Preparation and properties of a 3D printed nHA/PLA bone tissue engineering scaffold loaded with a ß-CD-CHX combined dECM hydrogel.

Jaw defects, which can result from a multitude of causes, significantly affect the physical well-being and psychological health of patients. The repair of these infected defects presents a formidable challenge in the clinical and research fields, owing to their intricate and diverse nature. This study aims to develop a personalized bone tissue engineering scaffold that synergistically offers antibacterial and osteogenic properties for treating infected maxillary defects. This study engineered a novel temperature-sensitive, sustained-release hydrogel by amalgamating ß-cyclodextrin (ß-CD) with chlorhexidine (CHX) and a decellularized extracellular matrix (dECM). This hydrogel was further integrated with a polylactic acid (PLA)-nano hydroxyapatite (nHA) scaffold, fabricated through 3D printing, to form a multifaceted composite scaffold (nHA/PLA/dECM/ß-CD-CHX). Drug release assays revealed that this composite scaffold ensures prolonged and sustained release. Bacteriological studies confirmed that the ß-CD-CHX loaded scaffold exhibits persistent antibacterial efficacy, thus effectively inhibiting bacterial growth. Moreover, the scaffold demonstrated robust mechanical strength. Cellular assays validated its superior biocompatibility, attributed to dECM and nHA components, significantly enhancing the proliferation, adhesion, and osteogenic differentiation of osteogenic precursor cells (MC3T3-E1). Consequently, the nHA/PLA/dECM/ß-CD-CHX composite scaffold, synthesized via 3D printing technology, shows promise in inducing bone regeneration, preventing infection, and facilitating the repair of jaw defects, positioning itself as a potential breakthrough in bone tissue engineering.

Preparation and Characterization of Carboxymethyl Chitosan/Sodium Alginate Composite Hydrogel Scaffolds Carrying Chlorhexidine and Strontium-Doped Hydroxyapatite.

Herein, we introduce a novel composite hydrogel scaffold designed for addressing infectious jaw defects, a significant challenge in clinical settings caused by the inherent limited self-regenerative capacity of bone tissues. The scaffold was engineered from a blend of carboxymethyl chitosan (CMCS)/sodium alginate (SA) hydrogel (CSH), ß-cyclodextrin/chlorhexidine clathrate (ß-CD-CHX), and strontium-nanohydroxyapatite nanoparticles (Sr-nHA). The ß-CD-CHX and Sr-nHA components were synthesized using a saturated aqueous solution and a coprecipitation method, respectively. Subsequently, these elements were encapsulated within the CSH matrix. Comprehensive characterization of the CMCS/SA/ß-CD-CHX/Sr-nHA composite hydrogel scaffold via scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy validated the successful synthesis. The swelling and in vitro degradation behaviors proved that the composite hydrogel had good physical properties, while in vitro evaluations demonstrated favorable biocompatibility and osteoinductive properties. Additionally, antibacterial assessments revealed its effectiveness against common pathogens, Staphylococcus aureus and Escherichia coli. Overall, our results indicate that the CMCS/SA/ß-CD-CHX/Sr-nHA composite hydrogel scaffolds exhibit significant potential for effectively treating infection-prone jaw defects.

Acidity-Triggered Charge-Convertible Conjugated Polymer for Dihydroartemisinin Delivery and Tumor-Specific Chemo-Photothermal Therapy.

Since the nonspecificity and nonselectivity of traditional treatment models lead to the difficulty of cancer treatment, nanobased strategies are needed to fill in the gaps of current approaches. Herein, a tumor microenvironment (TME)-responsive chemo-photothermal treatment model was developed based on dihydroartemisinin (DHA)-loaded conjugated polymers (DHA@PLGA-PANI). The synthesized DHA@PLGA-PANI exhibited enhanced photothermal properties under mild-acidic conditions and thus triggered local heat at the tumor site. Meanwhile, these iron-doped conjugated polymers of PLGA-PANI were used as the source of Fe, and benefiting from the Fe-dependent cytotoxicity of DHA, the burst of free radicals could be generated in tumors. Therefore, the combination of TME-responsive chemo-photothermal therapy could achieve effective tumor efficacy.

Local Destruction of Tumors for Systemic Immunoresponse: Engineering Antigen-Capturing Nanoparticles as Stimulus-Responsive Immunoadjuvants.

Immunotherapy has established a new paradigm for cancer treatment and made many breakthroughs in clinical practice. However, the rarity of immune response suggests that additional intervention is necessary. In recent years, it has been reported that local tumor destruction (LTD) can cause cancer cell death and induce an immunologic response. Thus, the combination of immunotherapy and LTD methods will be a promising approach to improve immune efficiency for cancer treatment. Herein, a nanobiotechnology platform to achieve high-precision LTD for systemic cancer immunotherapy has been successfully constructed. Possessing radio-sensitizing and photothermal properties, the engineered immunoadjuvant-loaded nanoplatform, which could precisely induce radiotherapy (RT)/photothermal therapy (PTT) to eliminate local tumor and meanwhile lead to the release of tumor-derived protein antigens (TDPAs), has been facilely fabricated by commercialized SPG membrane emulsification technology. Further on, the TDPAs could be captured and form personal nanovaccines in situ to serve as both reservoirs of antigen and carriers of immunoadjuvant, which can effectively improve the immune response. The investigations suggest that the combination of RT/PTT and improved immunotherapy using adjuvant-encapsulated antigen-capturing nanoparticles holds tremendous promise in cancer treatments.