Preparation of PLCL/ECM nerve conduits by electrostatic spinning technique and evaluationin vitroandin vivo.

Objective. Artificial nerve scaffolds composed of polymers have attracted great attention as an alternative for autologous nerve grafts recently. Due to their poor bioactivity, satisfactory nerve repair could not be achieved. To solve this problem, we introduced extracellular matrix (ECM) to optimize the materials.Approach.In this study, the ECM extracted from porcine nerves was mixed with Poly(L-Lactide-co-ϵ-caprolactone) (PLCL), and the innovative PLCL/ECM nerve repair conduits were prepared by electrostatic spinning technology. The novel conduits were characterized by scanning electron microscopy (SEM), tensile properties, and suture retention strength test for micromorphology and mechanical strength. The biosafety and biocompatibility of PLCL/ECM nerve conduits were evaluated by cytotoxicity assay with Mouse fibroblast cells and cell adhesion assay with RSC 96 cells, and the effects of PLCL/ECM nerve conduits on the gene expression in Schwann cells was analyzed by real-time polymerase chain reaction (RT-PCR). Moreover, a 10 mm rat (Male Wistar rat) sciatic defect was bridged with a PLCL/ECM nerve conduit, and nerve regeneration was evaluated by walking track, mid-shank circumference, electrophysiology, and histomorphology analyses.Main results.The results showed that PLCL/ECM conduits have similar microstructure and mechanical strength compared with PLCL conduits. The cytotoxicity assay demonstrates better biosafety and biocompatibility of PLCL/ECM nerve conduits. And the cell adhesion assay further verifies that the addition of ECM is more beneficial to cell adhesion and proliferation. RT-PCR showed that the PLCL/ECM nerve conduit was more favorable to the gene expression of functional proteins of Schwann cells. Thein vivoresults indicated that PLCL/ECM nerve conduits possess excellent biocompatibility and exhibit a superior capacity to promote peripheral nerve repair.Significance.The addition of ECM significantly improved the biocompatibility and bioactivity of PLCL, while the PLCL/ECM nerve conduit gained the appropriate mechanical strength from PLCL, which has great potential for clinical repair of peripheral nerve injuries.

Enhancing neuroinduction activity of PLCL-based nerve conduits through native epineurium integration.

Autologous nerve grafts have been considered the gold standard for peripheral nerve grafts. However, due to drawbacks such as functional loss in the donor area and a shortage of donor sources, nerve conduits are increasingly being considered as an alternative approach. Polymer materials have been widely studied as nerve repair materials due to their excellent processing performance. However, their limited biocompatibility has restricted further clinical applications. The epineurium is a natural extra-neural wrapping structure. After undergoing decellularization, the epineurium not only reduces immune rejection but also retains certain bioactive components. In this study, decellularized epineurium (DEP) derived from the sciatic nerve of mammals was prepared, and a bilayer nerve conduit was created by electrospinning a poly (l-lactide-co-ε-caprolactone) (PLCL) membrane layer onto the outer surface of the DEP. Components of the DEP were examined; the physical properties and biosafety of the bilayer nerve conduit were evaluated; and the functionality of the nerve conduit was evaluated in rats. The results demonstrate that the developed bilayer nerve conduit exhibits excellent biocompatibility and mechanical properties. Furthermore, this bilayer nerve conduit shows significantly superior therapeutic effects for sciatic nerve defects in rats compared to the pure PLCL nerve conduit. In conclusion, this research provides a novel strategy for the design of nerve regeneration materials and holds promising potential for further clinical translation.

Analysis of Individualized Silicone Rubber Bolus Using Fan Beam Computed Tomography in Postmastectomy Radiotherapy: A Dosimetric Evaluation and Skin Acute Radiation Dermatitis Survey.

Objective: To investigate the dosimetric effects of using individualized silicone rubber (SR) bolus on the target area and organs at risk (OARs) during postmastectomy radiotherapy (PMRT), as well as evaluate skin acute radiation dermatitis (ARD). Methods: A retrospective study was performed on 30 patients with breast cancer. Each patient was prepared with an individualized SR bolus of 3 mm thickness. Fan-beam computed tomography (FBCT) was performed at the first and second fractions, and then once a week for a total of 5 times. Dosimetric metrics such as homogeneity index (HI), conformity index (CI), skin dose (SD), and OARs including the heart, lungs, and spinal cord were compared between the original plan and the FBCTs. The acute side effects were recorded. Results: In targets' dosimetric metrics, there were no significant differences in Dmean and V105% between planning computed tomography (CT) and actual treatments (P > .05), while the differences in D95%, V95%, HI, and CI were statistically significant (P < .05). In OARs, there were no significant differences between the Dmean, V5, and V20 of the affected lung, V5 of the heart and Dmax of the spinal cord (P > .05) except the V30 of affected lung, which was slightly lower than the planning CT (P < .05). In SD, both Dmax and Dmean in actual treatments were increased than plan A, and the difference was statistically significant (P < .05), while the skin-V20 and skin-V30 has no difference. Among the 30 patients, only one patient had no skin ARD, and 5 patients developed ARD of grade 2, while the remaining 24 patients were grade 1. Conclusion: The OR bolus showed good anastomoses and high interfraction reproducibility with the chest wall, and did not cause deformation during irradiation. It ensured accurate dose delivery of the target and OARs during the treatment, which may increase SD by over 101%. In this study, no cases of grade 3 skin ARD were observed. However, the potential of using OR bolus to reduce grade 1 and 2 skin ARD warrants further investigation with a larger sample size.

Exploring polysaccharide and protein-enriched decellularized matrix scaffolds for tendon and ligament repair: A review.

Tissue engineering (TE) has become a primary research topic for the treatment of diseased or damaged tendon/ligament (T/L) tissue. T/L injuries pose a severe clinical burden worldwide, necessitating the development of effective strategies for T/L repair and tissue regeneration. TE has emerged as a promising strategy for restoring T/L function using decellularized extracellular matrix (dECM)-based scaffolds. dECM scaffolds have gained significant prominence because of their native structure, relatively high bioactivity, low immunogenicity, and ability to function as scaffolds for cell attachment, proliferation, and differentiation, which are difficult to imitate using synthetic materials. Here, we review the recent advances and possible future prospects for the advancement of dECM scaffolds for T/L tissue regeneration. We focus on crucial scaffold properties and functions, as well as various engineering strategies employed for biomaterial design in T/L regeneration. dECM provides both the physical and mechanical microenvironments required by cells to survive and proliferate. Various decellularization methods and sources of allogeneic and xenogeneic dECM in T/L repair and regeneration are critically discussed. Additionally, dECM hydrogels, bio-inks in 3D bioprinting, and nanofibers are briefly explored. Understanding the opportunities and challenges associated with dECM-based scaffold development is crucial for advancing T/L repairs in tissue engineering and regenerative medicine.

Progress and mechanism of graphene oxide-composited materials in application of peripheral nerve repair.

Peripheral nerve injuries (PNI) are one of the most common nerve injuries, and graphene oxide (GO) has demonstrated significant potential in the treatment of PNI. GO could enhance the proliferation, adhesion, migration, and differentiation of neuronal cells by upregulating the expression of relevant proteins, and regulate the angiogenesis process and immune response. Therefore, GO is a suitable additional component for fabricating artificial nerve scaffolds (ANS), in which the slight addition of GO could improve the physicochemical performance of the matrix materials, through hydrogen bonds and electrostatic attraction. GO-composited ANS can increase the expression of nerve regeneration-associated genes and factors, promoting angiogenesis by activating the RAS/MAPK and AKT-eNOS-VEGF signaling pathway, respectively. Moreover, GO could be metabolized and excreted from the body through the pathway of peroxidase degradation in vivo. Consequently, the application of GO in PNI regeneration exhibits significant potential for transitioning from laboratory research to clinical use.

Enantioselective α-Amination of Amides by One-Pot Organo-/Iodine Sequential Catalysis.

An one-pot organo- and iodine sequential catalysis strategy for reactions of amides with pyrazole-based primary amines was described to synthesize chiral α-amino amides with a quaternary stereocenter. This methodology exhibited strong asymmetric induction, resulting in a typical enantiomeric excess value exceeding 99% and diastereoselectivity up to >99:1 dr. Moreover, the reaction was conducted without the use of any metals or strong bases.

Multifunctional electrospun nanofibrous scaffold enriched with alendronate and hydroxyapatite for balancing osteogenic and osteoclast activity to promote bone regeneration.

Electrospun composite nanofiber scaffolds are well known for their bone and tissue regeneration applications. This research is focused on the development of PVP and PVA nanofiber composite scaffolds enriched with hydroxyapatite (HA) nanoparticles and alendronate (ALN) using the electrospinning technique. The developed nanofiber scaffolds were investigated for their physicochemical as well as bone regeneration potential. The results obtained from particle size, zeta potential, SEM and EDX analysis of HA nanoparticles confirmed their successful fabrication. Further, SEM analysis verified nanofiber's diameters within 200-250 nm, while EDX analysis confirmed the successful incorporation of HA and ALN into the scaffolds. XRD and TGA analysis revealed the amorphous and thermally stable nature of the nanofiber composite scaffolds. Contact angle, FTIR analysis, Swelling and biodegradability studies revealed the hydrophilicity, chemical compatibility, suitable water uptake capacity and increased in-vitro degradation making it appropriate for tissue regeneration. The addition of HA into nanofiber scaffolds enhanced the physiochemical properties. Additionally, hemolysis cell viability, cell adhesion and proliferation by SEM as well as confocal microscopy and live/dead assay results demonstrated the non-toxic and biocompatibility behavior of nanofiber scaffolds. Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) assays demonstrated osteoblast promotion and osteoclast inhibition, respectively. These findings suggest that developed HA and ALN-loaded PVP/PVA-ALN-HA nanofiber composite scaffolds hold significant promise for bone regeneration applications.

Biomimetic electrospun nanofibrous scaffold for tissue engineering: preparation, optimization by design of experiments (DOE), in-vitro and in-vivo characterization.

Electrospinning is a versatile method for fabrication of précised nanofibrous materials for various biomedical application including tissue engineering and drug delivery. This research is aimed to fabricate the PVP/PVA nanofiber scaffold by novel electrospinning technique and to investigate the impact of process parameters (flow rate, voltage and distance) and polymer concentration/solvent combinations influence on properties of electrospun nanofibers. The in-vitro and in-vivo degradation studies were performed to evaluate the potential of electrospun PVP/PVA as a tissue engineering scaffold. The solvents used for electrospinning of PVP/PVA nanofibers were ethanol and 90% acetic acid, optimized with central composite design via Design Expert software. NF-2 and NF-35 were selected as optimised nanofiber formulation in acetic acid and ethanol, and their characterization showed diameter of 150-400 nm, tensile strength of 18.3 and 13.1 MPa, respectively. XRD data revealed the amorphous nature, and exhibited hydrophilicity (contact angles: 67.89° and 58.31° for NF-2 and NF-35). Swelling and in-vitro degradability studies displayed extended water retention as well as delayed degradation. FTIR analysis confirmed solvent-independent interactions. Additionally, hemolysis and in-vitro cytotoxicity studies revealed the non-toxic nature of fabricated scaffolds on RBCs and L929 fibroblast cells. Subcutaneous rat implantation assessed tissue response, month-long biodegradation, and biocompatibility through histological analysis of surrounding tissue. Due to its excellent biocompatibility, this porous PVP/PVA nanofiber has great potential for biomedical applications.

Emerging Polymer-Based Nanosystem Strategies in the Delivery of Antifungal Drugs.

Nanosystems-based antifungal agents have emerged as an effective strategy to address issues related to drug resistance, drug release, and toxicity. Among the diverse materials employed for antifungal drug delivery, polymers, including polysaccharides, proteins, and polyesters, have gained significant attention due to their versatility. Considering the complex nature of fungal infections and their varying sites, it is crucial for researchers to carefully select appropriate polymers based on specific scenarios when designing antifungal agent delivery nanosystems. This review provides an overview of the various types of nanoparticles used in antifungal drug delivery systems, with a particular emphasis on the types of polymers used. The review focuses on the application of drug delivery systems and the release behavior of these systems. Furthermore, the review summarizes the critical physical properties and relevant information utilized in antifungal polymer nanomedicine delivery systems and briefly discusses the application prospects of these systems.

Preparation and assessment of an optimized multichannel acellular nerve allograft for peripheral nerve regeneration.

Peripheral nerve regeneration after injury is still a clinical problem. The application of autologous nerve grafting, the gold standard treatment, is greatly restricted. Acellular nerve allografts (ANAs) are considered promising alternatives, but they are difficult to achieve satisfactory therapeutic outcomes, which may be attributed to their compact inherent ultrastructure and substantial loss of extracellular matrix (ECM) components. Regarding these deficiencies, this study developed an optimized multichannel ANA by a modified decellularization method. These innovative ANAs were demonstrated to retain more ECM bioactive molecules and regenerative factors, with effective elimination of cellular antigens. The presence of microchannels with larger pore size allowed ANAs to gain higher porosity and better swelling performance, which improves their internal ultrastructure. Their mechanical properties were more similar to those of native nerves. Moreover, the optimized ANAs exhibited good biocompatibility and possessed significant advantages in supporting the proliferation and migration of Schwann cells in vitro. The in vivo results further confirmed their superior capacity to promote axon regrowth and myelination as well as restore innervation of target muscles, leading to better functional recovery than the conventional ANAs. Overall, this study demonstrates that the optimized multichannel ANAs have great potential for clinical application and offer new insight into the further improvement of ANAs.

Unique Chirality Selection in Neural Cells for D-Matrix Enabling Specific Manipulation of Cell Behaviors.

Manipulating neural cell behaviors is a critical issue to various therapies for neurological diseases and damages, where matrix chirality has long been overlooked despite the proven adhesion and proliferation improvement of multiple non-neural cells by L-matrixes. Here, it is reported that the D-matrix chirality specifically enhances cell density, viability, proliferation, and survival in four different types of neural cells, contrasting its inhibition in non-neural cells. This universal impact on neural cells is defined as "chirality selection for D-matrix" and is achieved through the activation of JNK and p38/MAPK signaling pathways by the cellular tension relaxation resulting from the weak interaction between D-matrix and cytoskeleton proteins, particularly actin. Also, D-matrix promotes sciatic nerve repair effectively, both with or without non-neural stem cell implantation, by improving the population, function, and myelination of autologous Schwann cells. D-matrix chirality, as a simple, safe, and effective microenvironment cue to specifically and universally manipulate neural cell behaviors, holds extensive application potential in addressing neurological issues such as nerve regeneration, neurodegenerative disease treatment, neural tumor targeting, and neurodevelopment.

Hydroxyapatite nanoparticles promote TLR4 agonist-mediated anti-tumor immunity through synergically enhanced macrophage polarization.

Macrophages represent the most prevalent immune cells in the tumor micro-environment, making them an appealing target for tumor immunotherapy. One of our previous studies showed that hydroxyapatite nanoparticles (HANPs) enhanced Toll-like receptor 4 (TLR4) signal transduction in macrophages. This study was proposed to investigate how HANPs manipulated the phenotype and function of macrophage against 4T1 breast tumors in the presence or absence of MPLA, a low toxic Toll-like receptor 4 (TLR4) agonist. The results demonstrated that the addition of HANPs to MPLA significantly promoted cytokine secretion and macrophage polarization toward a tumoricidal M1 phenotype. Further, the resulting supernatant from HANPs/MPLA co-stimulated macrophages enhanced 4T1 tumor cells apoptosis compared to that from macrophages treated with a single component or PBS control. In particular, we found HANPs elicited immunogenic cell death (ICD) indicated by the increased expression of "danger signals", including HMGB1, CRT and ATP in 4T1 cells. Subsequently, the ICD derivatives-containing supernatant from HANPs-treated 4T1 cells activated macrophage and shifted the phenotype of the cells toward M1 type. Moreover, in a tumor-bearing mice model, HANPs and MPLA synergistically delayed tumor growth compared to PBS control, which was positively associated with the promoted macrophage polarization and ICD induction. Therefore, our findings demonstrated a potential platform to modulate the function of macrophages, and shed a new insight into the mechanism involving the immunomodulatory effect of HANPs for tumor therapy. STATEMENT OF SIGNIFICANCE: Polarizing macrophage toward tumoricidal phenotype by harnessing Toll-like receptor (TLR) agonists has been proven effective for tumor immunotherapy. However, the immunomodulatory potency of TLR agonists is limited due to immune suppression or tolerance associated with TLR activation in immune cells. Herein, we introduced hydroxyapatite nanoparticles (HANPs) to MPLA, a TLR4 agonist. The results demonstrated that the addition of HANPs to MPLA promoted macrophage shift toward tumoricidal M1 phenotype, supported a "hot" tumor transformation, and delayed 4T1 tumor growth. Moreover, we found that HANPs elicited immunogenic cell death that produced "danger" signals from cancer cells thereby further facilitated macrophage polarization. This work is significant to direct the rational design of HANPs coupled with or without TLR agonists for tumor immunotherapy.

Nerve ECM and PLA-PCL based electrospun bilayer nerve conduit for nerve regeneration.

Introduction: The porcine nerve-derived extracellular matrix (ECM) fabricated as films has good performance in peripheral nerve regeneration. However, when constructed as conduits to bridge nerve defects, ECM lacks sufficient mechanical strength. Methods: In this study, a novel electrospun bilayer-structured nerve conduit (BNC) with outer poly (L-lactic acid-co-ε-caprolactone) (PLA-PCL) and inner ECM was fabricated for nerve regeneration. The composition, structure, and mechanical strength of BNC were characterized. Then BNC biosafety was evaluated by cytotoxicity, subcutaneous implantation, and cell affinity tests. Furthermore, BNC was used to bridge 10-mm rat sciatic nerve defect, and nerve functional recovery was assessed by walking track, electrophysiology, and histomorphology analyses. Results: Our results demonstrate that BNC has a network of nanofibers and retains some bioactive molecules, including collagen I, collagen IV, laminin, fibronectin, glycosaminoglycans, nerve growth factor, and brain-derived neurotrophic factor. Biomechanical analysis proves that PLA-PCL improves the BNC mechanical properties, compared with single ECM conduit (ENC). The functional evaluation of in vivo results indicated that BNC is more effective in nerve regeneration than PLA-PCL conduit or ENC. Discussion: In conclusion, BNC not only retains the good biocompatibility and bioactivity of ECM, but also obtains the appropriate mechanical strength from PLA-PCL, which has great potential for clinical repair of nerve defects.

Synthetic biodegradable polymer materials in the repair of tumor-associated bone defects.

The repair and reconstruction of bone defects and the inhibition of local tumor recurrence are two common problems in bone surgery. The rapid development of biomedicine, clinical medicine, and material science has promoted the research and development of synthetic degradable polymer anti-tumor bone repair materials. Compared with natural polymer materials, synthetic polymer materials have machinable mechanical properties, highly controllable degradation properties, and uniform structure, which has attracted more attention from researchers. In addition, adopting new technologies is an effective strategy for developing new bone repair materials. The application of nanotechnology, 3D printing technology, and genetic engineering technology is beneficial to modify the performance of materials. Photothermal therapy, magnetothermal therapy, and anti-tumor drug delivery may provide new directions for the research and development of anti-tumor bone repair materials. This review focuses on recent advances in synthetic biodegradable polymer bone repair materials and their antitumor properties.

Sequential expression of miR-221-3p and miR-338-3p in Schwann cells as a therapeutic strategy to promote nerve regeneration and functional recovery.

The functional properties of endogenous Schwann cells (SCs) during nerve repair are dynamic. Optimizing the functional properties of SCs at different stages of nerve repair may have therapeutic benefit in improving the repair of damaged nerves. Previous studies showed that miR-221-3p promotes the proliferation and migration of SCs, and miR-338-3p promotes the myelination of SCs. In this study, we established rat models of sciatic nerve injury by bridging the transected sciatic nerve with a silicone tube. We injected a miR-221 lentiviral vector system together with a doxycycline-inducible Tet-On miR-338 lentiviral vector system into the cavity of nerve conduits of nerve stumps to sequentially regulate the biological function of endogenous SCs at different stages of nerve regeneration. We found that the biological function of SCs was sequentially regulated, the diameter and density of myelinated axons were increased, the expression levels of NF200 and myelin basic protein were increased, and the function of injured peripheral nerve was improved using this system. miRNA Target Prediction Database prediction, Nanopore whole transcriptome sequencing, quantitative PCR, and dual luciferase reporter gene assay results predicted and verified Cdkn1b and Nrp1 as target genes of miR-221-3p and miR-338-3p, respectively, and their regulatory effects on SCs were confirmed in vitro. In conclusion, here we established a new method to enhance nerve regeneration through sequential regulation of biological functions of endogenous SCs, which establishes a new concept and model for the treatment of peripheral nerve injury. The findings from this study will provide direct guiding significance for clinical treatment of sciatic nerve injury.

On the Core Prescriptions and Their Mechanisms of Traditional Chinese Medicine in Hepatitis B, Liver Cirrhosis, and Liver Cancer Treatment.

Background: As a frequent cause of death in cancer patients, liver cancer usually occurs in hepatitis B and cirrhosis. In China, Chinese people have been using traditional Chinese medicine (TCM) in treating various chronic liver diseases, which could effectively improve the symptoms and slow down the progression of liver diseases. However, due to the complexity rules of TCM prescription, their action mechanisms are still not clearly understood, which may affect the popularization of effective prescriptions. This study aims to identify the core TCM herbs in the treatment of hepatitis B, liver cirrhosis, and liver cancer so as to clarify the mechanism of action of the core herb networks. Methods: There were 1,673 prescriptions for chronic liver diseases collected in this study, of which 854 were hepatic B prescriptions, 530 were for liver cirrhosis, and 289 were for liver cancer. The basic characteristics of herbal medicine were firstly explained via descriptive analysis, then the core prescriptions of herbal medicine were analyzed through association rule, and finally, the mechanism of core prescriptions was explored with the help of systematic network pharmacology and by applying such databases as TCMIP, HERB, OMIM, GeneCards, KEGG, and software like RStudio and Cytoscape. Results: The rule of the core prescriptions in these cases was characterized by the application of herbs with both cold and warm properties, in which bitter herbs with cold property took priority. Tonifying deficiency, clearing heat, and activating blood circulations to remove stasis were common treatment principles for the three liver diseases. Turmeric Root Tuber (YuJin), White Peony Root (BaiShao), Bupleurum (ChaiHu), Salvia miltiorrhiza (DanShen), and Astragali Radix (HuangQi) were prescribed the most in hepatitis B treatment to invigorate the spleen and soothe the liver. Astragali Radix (HuangQi), Tuckahoe (FuLing), Atractylodis Macrocephalae Rhizoma (BaiZhu), Fructus Polygoni Orientalis (ShuiHongHuaZi), and Curcumae Rhizome (EZhu) were most frequently applied in liver cirrhosis treatment to replenish qi and activate blood. Oldenlandia (BaiHuaSheSheCao), Bearded Scutellaria (BanZhiLian), Curcumae Rhizome (EZhu), and Cardamom (DouKou) were most frequently prescribed to eliminate cancer toxin, invigorate the spleen, and activate blood. These core herbs mainly act through signal transduction and immune system pathways, in which the PI3K-Akt pathway plays a key role. The core prescription for liver cirrhosis regulated more endocrine system pathways than the hepatitis B prescription, and liver cancer prescription regulated more nervous system-related pathways. Conclusion: Three core prescriptions for hepatitis B, liver cirrhosis, and liver cancer treatment were identified, which acted mainly through signal transduction and immune system pathways to regulate immunity and cell growth and participate in inflammation inhibition, in which liver cancer prescription regulated more pathways, especially more nervous system-related pathways than the other two.

Significance of Capping Agents of Colloidal Nanoparticles from the Perspective of Drug and Gene Delivery, Bioimaging, and Biosensing: An Insight.

The over-growth and coagulation of nanoparticles is prevented using capping agents by the production of stearic effect that plays a pivotal role in stabilizing the interface. This strategy of coating the nanoparticles' surface with capping agents is an emerging trend in assembling multipurpose nanoparticles that is beneficial for improving their physicochemical and biological behavior. The enhancement of reactivity and negligible toxicity is the outcome. In this review article, an attempt has been made to introduce the significance of different capping agents in the preparation of nanoparticles. Most importantly, we have highlighted the recent progress, existing roadblocks, and upcoming opportunities of using surface modified nanoparticles in nanomedicine from the drug and gene delivery, bioimaging, and biosensing perspectives.

Hydroxyapatite nanoparticles drive the potency of Toll-like receptor 9 agonist for amplified innate and adaptive immune response.

The potency of Toll-like receptor 9 (TLR9) agonist to drive innate immune response was limited due to immune suppression or tolerance during TLR9 signaling activation in immune cells. Herein we addressed this problem by introducing hydroxyapatite nanoparticles (HANPs) to CpG ODN (CpG), a TLR9 agonist. The study revealed that HANPs concentration and duration-dependently reprogramed the immune response by enhancing the secretion of immunostimulatory cytokines (tumor necrosis factor α (TNFα) or IL-6) while reducing the production of immunosuppressive cytokine (IL-10) in macrophages in response to CpG. Next, the enhanced immune response benefited from increased intracellular Ca2+ in macrophage by the addition of HANPs. Further, we found exposure to HANPs impacted the mitochondrial function of macrophages in support of the synthesis of adenosine triphosphate (ATP), the production of nicotinamide adenine dinucleotide (NAD), and reactive oxygen species (ROS) in the presence or absence of CpG. In vaccinated mice model, only one vaccination with a mixture of CpG, HANPs, and OVA, a model antigen, allowed the development of a long-lasting balanced humoral immunity in mice without any histopathological change in the local injection site. Therefore, this study revealed that HANPs could modulate the intracellular calcium level, mitochondrial function, and immune response in immune cells, and suggested a potential combination adjuvant of HANPs and TLR9 agonist for vaccine development. Electronic Supplementary Material: Supplementary material (TEM image, LDH activity, the Ca2+ release in PBS, qRT-PCR analysis, H&E staining, and IL-6 level in the injection site and serum) is available in the online version of this article at 10.1007/s12274-022-4683-x.

Electron ultra-high dose rate FLASH irradiation study using a clinical linac: Linac modification, dosimetry, and radiobiological outcome.

PURPOSE: Ultra-high dose rate FLASH irradiation (FLASH-IR) has been shown to cause less normal tissue damage compared with conventional irradiation (CONV-IR), this is known as the "FLASH effect." It has attracted immense research interest because its underlying mechanism is scarcely known. The purpose of this study was to determine whether FLASH-IR and CONV-IR induce differential inflammatory cytokine expression using a modified clinical linac. MATERIALS AND METHODS: An Elekta Synergy linac was used to deliver 6 MeV CONV-IR and modified to deliver FLASH-IR. Female FvB mice were randomly assigned to three different groups: a non-irradiated control, CONV-IR, or FLASH-IR. The FLASH-IR beam was produced by single pulses repeated manually with a 20-s interval (Strategy 1), or single-trigger multiple pulses with a 10 ms interval (Strategy 2). Mice were immobilized in the prone position in a custom-designed applicator with Gafchromic films positioned under the body. The prescribed doses for the mice were 6 to 18 Gy and verified using Gafchromic films. Cytokine expression of three pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], interleukin-6 [IL-6]) and one anti-inflammatory cytokine (IL-10) in serum samples and skin tissue were examined within 1 month post-IR. RESULTS: The modified linac delivered radiation at an intra-pulse dose rate of around 1 × 106 Gy/s and a dose per pulse over 2 Gy at a source-to-surface distance (SSD) of 13 to 15 cm. The achieved dose coverage was 90%-105% of the maximum dose within -20 to 20 mm in the X direction and 95% within -30 to 30 mm in the Y direction. The absolute deviations between the prescribed dose and the actual dose were 2.21%, 6.04%, 2.09%, and 2.73% for 6, 9, 12, and 15 Gy as measured by EBT3 films, respectively; and 4.00%, 4.49%, and 2.30% for 10, 14, and 18 Gy as measured by the EBT XD films, respectively. The reductions in the CONV-IR versus the FLASH-IR group were 4.89%, 10.28%, -7.8%, and -22.17% for TNF-α, IFN-γ, IL-6, and IL-10 in the serum on D6, respectively; 37.26%, 67.16%, 56.68%, and -18.95% in the serum on D31, respectively; and 62.67%, 35.65%, 37.75%, and -12.20% for TNF-α, IFN-γ, IL-6, and IL-10 in the skin tissue, respectively. CONCLUSIONS: Ultra-high dose rate electron FLASH caused lower pro-inflammatory cytokine levels in serum and skin tissue which might mediate differential tissue damage between FLASH-IR and CONV-IR.