GCR-Net:3D Graph convolution-based residual network for robust reconstruction in cerenkov luminescence tomography

Cerenkov Luminescence Tomography(CLT)is a novel and potential imaging modality which can display the three-dimensional distribution of radioactive probes.However,due to severe ill-posed inverse problem,obtaining accurate reconstruction results is still a challenge for traditional model-based methods.The recently emerged deep learning-based methods can directly learn the mapping relation between the surface photon intensity and the distribution of the radioactive source,which effectively improves the performance of CLT reconstruction.However,the previously proposed deep learning-based methods cannot work well when the order of input is disarranged.In this paper,a novel 3D graph convolution-based residual network,GCR-Net,is proposed,which can obtain a robust and accurate reconstruction result from the photon intensity of the surface.Additionally,it is proved that the network is insensitive to the order of input.The performance of this method was evaluated with numerical simulations and in vivo experiments.The results demonstrated that compared with the existing methods,the proposed method can achieve efficient and accurate reconstruction in localization and shape recovery by utilizing threedimensional information.

Promoting chondrogenesis by targeted delivery to the degenerating cartilage in early treatment of osteoarthritis

Osteoarthritis(OA)is a highly incident total joint degenerative disease with cartilage degeneration as the primary pathogenesis.The cartilage matrix is mainly composed of collagen,a matrix protein with a hallmark triplehelix structure,which unfolds with collagen degradation on the cartilage surface.A collagen hybridizing peptide(CHP)is a synthetic peptide that binds the denatured collagen triple helix,conferring a potential diseasetargeting possibility for early-stage OA.Here,we constructed an albumin nanoparticle(An)conjugated with CHP,loaded with a chondrogenesis-promoting small molecule drug,kartogenin(KGN).The CHP-KGN-An particle exhibited sustained release of KGN in vitro and prolonged in vivo retention selectively within the degenerated cartilage in the knee joints of model mice with early-stage OA.Compared to treatment with KGN alone,CHP-KGN-An robustly attenuated cartilage degradation,synovitis,osteophyte formation,and subchondral bone sclerosis in OA model mice and exhibited a more prominent effect on physical activity improvement and pain alleviation.Our study showcases that targeting the degenerated cartilage by collagen hybridization can remarkably promote the efficacy of small molecule drugs and may provide a novel delivery strategy for earlystage OA therapeutics.

Cerium oxide nanozymes alleviate oxidative stress in tenocytes for Achilles tendinopathy healing

Background:Reactive oxygen species(ROS)is considered as ubiquitous and highly active chemicals that influence tendon integrity and orchestrate tendon repair.With significant recent advances in nanomaterials,cerium oxide nanoparticles(CeO_(2)NPs)exhibit superoxide dismutase-and catalase-like activities.Herein,we introduced a therapeutic approach of CeO_(2)NPs for Achilles tendinopathy(AT)healing.Methods:CeO_(2)NPs were synthesized to examine their effect as ROS scavengers on AT healing in vitro and in vivo.The mRNA levels of inflammatory factors were evaluated in AT after CeO_(2)NPs treatment in vitro.The mechanisms underlying CeO_(2)NPs-mediated stimulation of NRF2 translocation and ERK signaling were verified through immunofluorescence and Western blot analysis.The efficacy of CeO_(2)NPs was tested in an AT rat model in comparison with the control.Results:CeO_(2)NPs not only significantly scavenged multiple ROS and suppressed ROS-induced inflammatory reactions but also protected cell proliferation under oxidative stress induced by tert-butyl hydroperoxide(TBHP).Moreover,CeO_(2)NPs could promote NRF_(2)nuclear translocation for anti-oxidation and anti-inflammation through the ERK signaling pathway.In a rat model of collagenase-induced tendon injuries,CeO_(2)NPs showed significant therapeutic efficacy by ameliorating tendon damage.Conclusion:The present study provides valuable insights into the molecular mechanism of CeO_(2)NPs to ameliorate ROS in tenocytes via the ERK/NRF_(2)signaling pathway,which underscores the potential of CeO_(2)NPs for application in the treatment of enthesopathy healing.