Exploratory study on the individualized application of eltrombopag in paediatric immune thrombocytopaenia guided by therapeutic drug monitoring.

There are variations in individual eltrombopag concentrations that may impact efficacy and adverse drug reactions (ADRs) in paediatric immune thrombocytopaenia (ITP). To solve this problem, we tailored the eltrombopag dosage refer to concentration, then followed up to assess concentration value in paediatric ITP. This is a single-centre, prospective, observational study. The eltrombopag dosage was adjusted, and children were divided into three groups: the maintenance, discontinuation, and increase groups. Concentration and other data were compared to explore concentration value in guiding the individualized treatment of paediatric ITP. Thirty-nine patients were enrolled, including 23 in the maintenance group, 3 in the discontinued group and 13 in the increase group. 3 patients discontinued eltrombopag due to ADRs, which was significantly higher than patients in the maintenance group (t = 3.606, p = 0.001). In all, 13 patients increased their dosage due to poor response, whose concentration and platelet count were significantly lower than patients in the maintenance group (t = 2.461, p = 0.019; t = 4.633, p < 0.001). Two months after the increase, the number of patients reaching CR and R respectively increased by 2 and 3, while the median platelet count was significantly raised (Z = -2.411, p = 0.016). Concentration could be used as a reference index for the individualized treatment of eltrombopag in paediatric ITP.

The early and rapid response to daratumumab in children with chronic refractory immune thrombocytopenia from a referral single centre of China.

Chronic refractory primary immune thrombocytopenia (CRITP) is currently defined as refractory to multiple therapeutic of second-line agents with or without splenectomy, faced with the threat of severe bleeding and challenging to obtain effective treatment. Although stable and effective drug therapy is needed, it is tough to find one. Daratumumab (Dara), an anti-CD38 monoclonal antibody presented the target cloned plasma cells in multiple myeloma, has also been reported to be effective in refractory autoimmune cytopenia in some case or series reports and ongoing clinical trials for adult patients with CRITP. Here, we report the early and durable response of Dara combination with avatrombopag in three CRITP patients (2 male and 1 female aged 12, 5 and 7 years, respectively) in our centre, with a follow-up period of more than 25 weeks. Before Dara, the duration of immune thrombocytopenia was 9, 1.4 and 4 years, respectively, a baseline platelet count of 4, 6, 9 × 109/L, the bleeding score was all above level 2 and the number of previous drugs was >3. The time to response (R: Plt ≥30 × 109/L with at least a twofold increase in the baseline count) of Dara was on Day 45, 6 and 4 and achieved complete response (CR: Plt ≥100 × 109/L) on Day 51, 6 and 8, the sustained response (SR: Plt >30 × 109/L following Dara at ≥75% of the platelet count assessment at follow-up end-point since the patient achieved response) was 48, 175 and 204 days with the follow-up time of 39.1, 25.9 and 29.7 weeks. The bleeding score decreased from grade 3 to grade 0 during follow-up. No significant treatment-related adverse events were found during follow-up. Dara combination with avatrombopag may be a safe and efficacious therapy for children with CRITP, but it needs to be further explored.

Long-term eltrombopag in children with chronic immune thrombocytopenia: A single-centre extended real-life observational study in China.

We have previously confirmed the efficacy and safety of eltrombopag (ELT) in children with chronic immune thrombocytopenia (cITP). However, data on both long-term exposure and early use of TPO-RAs are lacking, so further 'field-practice' evidence on treatment is required. Here, we report the long-term follow-up results (between September 2018 and June 2023) of our previous study. The main objective of this study was to retrospectively review our large institutional experience with ITP patients previously enrolled in our paediatric cITP study. We had more than 3 years of follow-up by June 2023 for treatment patterns and outcomes. A total of 65 patients (28 males) were enrolled, with a median age at ELT initiation of 6.34 (range 1.65, 14.13) years and a follow-up of 47.07 (36.00, 57.00) months, with 40.36 (10.53, 56.83) months of ELT therapy at the time of analysis. In total, 29.23% (19/65) of patients discontinued ELT due to stable response, and 18.46% (12/65) of patients switched to other ITP therapies due to loss of response (LOR) after 19.13 (14.53, 26.37) months. Of the 19 patients who discontinued ELT due to a stable response, 24.62% (16/65) achieved a 12 m sustained response off-treatment (SRoT); the last recorded platelet count ranged from 56 to 166 × 109 /L (median 107 × 109/L); and 4.62% (3/65) patients relapsed at 5, 6 and 9 months after discontinuation. Of the 12 patients who LOR to ELT after 19.13 (14.53, 26.37) months of therapy, four switched to avatrombopag, three switched to hetrombopag, two switched to traditional Chinese medicine (TCM), one underwent splenectomy and two received additional prednisolone under ELT treatment. Thirty-four patients who tapered and maintained a durable response. The patients with LOR and the patients with tapering were compared; the platelet count at the start of ELT is lower, and the time to response is longer in the patients with LOR. The platelet count at the start of ELT and the time to response may be the predictive factors for LOR during ELT treatment. We report more than 3 years of long-term clinical data on children with cITP using ELT. These data do not raise any new safety concerns regarding the long-term use of ELT in children with cITP.

Efficacy and safety of avatrombopag in Chinese children with persistent and chronic primary immune thrombocytopenia: A multicentre observational retrospective study in China.

Avatrombopag (AVA) is a novel thrombopoietin receptor agonist (TPO-RA) that has been recently approved as a second-line therapy for immune thrombocytopenia (ITP) in adults; however, its safety and efficacy data in children are lacking. Here, we demonstrated the efficacy and safety of AVA as second-line therapy in children with ITP. A multicentre, retrospective, observational study was conducted in children with persistent or chronic ITP who did not respond to or relapsed from previous treatment and were treated with AVA for at least 12 weeks between August 2020 and December 2022. The outcomes were the responses (defined as achieving a platelet count ≥30 × 109/L, twofold increase in platelet count from baseline and absence of bleeding), including rapid response within 4 weeks, sustained response at weeks 12 and 24, bleeding control and adverse events (AEs). Thirty-four (18 males) patients with a mean age of 6.3 (range: 1.9-15.3) years were enrolled. The median number of previous treatment types was four (range: 1-6), and 41.2% patients switched from other TPO-RAs. Within 4 weeks, overall response (OR) was achieved in 79.4% patients and complete response (CR, defined as a platelet count ≥100 × 109/L and the absence of bleeding) in 67.7% patients with a median response time of 7 (range: 1-27) days. At 12 weeks, OR was achieved in 88.2%, CR in 76.5% and sustained response in 44% of patients. At 24 weeks, 22/34 (64.7%) patients who achieved a response and were followed up for 24 weeks were evaluated; 12/22 (54.55%) achieved a sustained response. During AVA therapy, median platelet counts increased by week 1 and were maintained throughout the treatment period. The proportion of patients with grade 1-3 bleeding decreased from 52.95% at baseline to 2.94% at 12 weeks, while concomitant ITP medications decreased from 36.47% at baseline to 8.82% at 12 weeks, with only 9 (26.47%) patients receiving rescue therapy 23 times within 12 weeks. There were 61.8% patients with 59 AEs: 29.8% with Common Terminology Criteria for Adverse Events grade 1 and the rest with grade 2. These findings show that AVA could achieve a rapid and sustained response in children with persistent or chronic ITP as a second-line treatment, with good clinical bleeding control and reduction of concomitant ITP therapy, without significant AEs.

Case report:Clinical manifestations and therapeutic options following rhTPO-induced neutralizing antibody production in a child with immune thrombocytopenia.

Recombinant human thrombopoietin (rhTPO) is commonly used to improve low platelet status in immune thrombocytopenia (ITP), as one protein product, even with a very low rate, there is still the possibility to produce neutralizing antibodies of thrombopoietin (TPO). We described a 7-year-old boy with ITP and normal TPO levels who had previously received rhTPO for 2 weeks but showed persistent thrombocytopenia and was misdiagnosed as acquired amegakaryocytic thrombocytopenia (AATP) and ineffectively treated with cyclosporine A (CsA) in combination with avatrombopag (AVA). As suspicious the TPO neutralizing antibody development as re-test of TPO level is 0, the CD20 + deletion antibody drug rituximab (RTX) was prescribed and received efficacy. rhTPO serves as one bio-protein drug and should be cautious with developing neutralizing antibodies if the drug effect is lost. The tests for antibody and/or TPO level should be done for the diagnosis, and the antibody eradication medication as an anti-CD20 antibody, RTX, should be prescribed to delete thes e neutralizing antibodies to recover the TPO level to reattain the response of ITP treatment.

Outcomes of switching to avatrombopag following treatment failure with eltrombopag in paediatric immune thrombocytopenia: A real-world study in China.

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia and a haemorrhagic risk. Thrombopoietin receptor agonists (TPO-RAs) are highly effective for ITP and are widely used to treat patients with steroid treatment failure or dependency. However, although treatment response to TPO-RAs may differ according to the type, the potential impact of switching from eltrombopag (ELT) to avatrombopag (AVA) with respect to efficacy or tolerance in children remains unknown. This study aimed to evaluate the outcomes of switching from ELT to AVA in paediatric patients with ITP. We retrospectively evaluated children with chronic immune thrombocytopenia (cITP) switched from ELT to AVA owing to treatment failure at the Hematology-Oncology Center of Beijing Children's Hospital between July 2021 and May 2022. Overall, 11 children (seven and four boys and girls respectively) with a median age of 8.3 (range: 3.8-15.3) years were included. The overall response and complete response (platelet [PLT] count ≥100 × 109 /L) rates during AVA treatment were 81.8% (9/11) and 54.6% (6/11) respectively. The median PLT count was significantly increased from ELT to AVA (7 [range: 2-33] × 109 /L vs. 74 [15-387] × 109 /L; p = 0.007). The median time to PLT count ≥30 × 109 /L was 18 (range: 3-120) days. Overall, 7/11 patients (63.6%) used concomitant medications, and concomitant medication use was gradually discontinued within 3-6 months after AVA initiation. In conclusion, AVA after ELT is effective in the heavily pretreated paediatric cITP population, with high response rates even in those with an inadequate response to a prior TPO-RA.

Transient increase in platelet counts associated with COVID-19 infection during TPO-RA as the second-line treatment in children with ITP.

The thrombopoietin receptor agonists (TPO-RA) were recommended for primary immune thrombocytopenia (ITP) during the pandemic of COVID-19. However, the incidence of thrombocytosis and thrombosis was sporadically reported in the chronic immune thrombocytopenia (CITP) patients receiving TPO-RA during the COVID-19 infection. With the local prevalence of COVID-19 in December 2022 in the Beijing area, we got more powerful evidence about the change in platelet (Plt) counts associated with COVID-19 infection. A single-centre observational cohort study was performed from the beginning of December 2022 to the end of February 2023 to enrol CITP children treated with TPO-RA alone as the second-line treatment and suffering from the COVID-19 infection in December 2022. The Plt counts before, during and after COVID-19 infection were collected. In total, 67 (34 males and 33 females) patients with 8.10 (2.15, 15.70) years of age were enrolled. Sixty-three patients who had responded to the TPO-RA showed a transient increase in Plt counts after the infection of COVID-19. The time of starting to increase was on Day 3 (2, 7), and to the peak level on Day 14 (7, 19) of infection with the peak Plt count was 289 (88, 1974) × 109 /L. With at least 2 months observation period from COVID-19 infection, the Plt counts of 100% (63/63) patients declined to the baseline on Day 25 (14, 41). The phenomenon of transient increase in Plt counts has been shown in the CITP children who responded to TPO-RA when suffering from COVID-19 infection.

Sustained response off treatment in eltrombopag for children with persistent/chronic primary immune thrombocytopenia: A multicentre observational retrospective study in China.

Eltrombopag (ELT) is effective and safe in adult persistent/chronic immune thrombocytopenia (p/cITP); a proportion could achieve a sustained response off treatment (SRoT); however, data on children are lacking. We attempted to analyse SRoT of ELT in children with p/cITP in this study. A multicentre retrospective observational study was performed in November 2022 for children with p/cITP who used ELT alone for >2 months between January 2017 and November 2021. Clinical data of pre-, during and post-ELT were collected. SRoT was defined as maintaining a platelet count of ≥30 × 109 /L without rescue therapy for at least 6 months off ELT. There were 143 patients enrolled; 69.2% (99/143) achieved an overall response of 43.3% and 25.9% achieved complete response (CR) and response (R). Among the 35 patients analysed from whom ELT was withdrawn, 71.4% (25/35) showed SRoT after discontinuing ELT without additional ITP therapy, with a median follow-up of 0.94 (range, 0.53-3.8) years, equal to 17.5% (25/143) in all patients treated with ELT. Compared with the patients with relapse (n = 10), the SRoT patients (n = 25) had a higher rate of CR (80% [20/25] vs. 40% [4/10]), shorter interval time from initiation to taper (6.4 months vs. 9.4 months), longer time from taper to withdrawal (1.1 years vs. 0.3 years) and a longer duration of ELT treatment (1.6 years vs. 0.5 years) with p < 0.05. Patients who achieved CR could attain SRoT more easily (p = 0.02). ELT had a response in 69.2% of children with p/cITP and 17.5% of them attained SRoT with good tolerance. The patients who achieved CR and began ELT treatment as early as possible, with a longer treatment duration and slower tapering, had a higher probability of SRoT.

Analysis of 85 Cases of Minimal Media Lower Hemisternotomy for Congenital Cardiac Surgery Under Cardiopulmonary Bypass in Infants.

OBJECTIVE: To investigate the feasibility and effect of minimal media lower hemisternotomy for cardiac surgery under cardiopulmonary bypass (CPB) in infant congenital heart disease. METHODS: In our hospital from May 2019 to October 2019, 170 infants with congenital heart disease underwent surgical treatment (median age 6.6 months; weight 6.0 kg). They were divided into 2 groups: those with conventional chest median incision and those with minimal sternotomy. Minimal lower hemisternotomy began from the third intercostal level and ended 0.5 cm above the xiphoid, just enough to insert a small sternal distractor. RESULTS: There was no significant difference between the 2 groups in CPB time. The operation time of small incision group was slightly longer (P < .05). There was no difference in prognosis between the 2 groups, but the wound length of the small incision group was significantly reduced (4.0 ± 0.5 versus 7.8 ± 0.8 cm, P < .05). Time of intensive care unit and hospital stay was shorter among hemisternotomy patients at a statistically significant level (P < .05). CONCLUSION: Minimal media lower hemisternotomy with the basic advantages of the sternal incision can expose the various parts of the heart, which meets most cardiac exploration and surgical operation needs, and the incision may still be extended if necessary. Lower hemisternotomy appears to be a safe, effective, and versatile alternative for many surgical interventions in infants with congenital heart disease.

Intraglandular Transplantation of Adipose-Derived Stem Cells for the Alleviation of Irradiation-Induced Parotid Gland Damage in Miniature Pigs.

PURPOSE: In a previous study, the authors verified the protective efficacy of adipose-derived stem cells (ADSCs) on the prevention of salivary gland (SG) damage induced by irradiation in mice. As a critical step before implementation in clinical practice, the present study investigated the protective effect of ADSCs in a miniature pig SG model, because miniature pigs share many characteristics with humans. MATERIALS AND METHODS: Third-passage autologous ADSCs at a concentration of 4 × 106 cells/mL were transplanted by intraglandular injection into parotid glands (PGs) immediately after local irradiation at a single dose of 20 Gy. The injection process was repeated twice a week for 6 consecutive weeks. At 12 weeks after irradiation, functional and histologic evaluations were performed by measuring salivary flow rate (SFR) and hematoxylin and eosin and periodic acid-Schiff staining. Immunohistochemical and transmission electron microscopic examinations also were conducted to evaluate amylase (AMY) production, microvessel density (MVD), and microstructural changes. RESULTS: The irradiated PGs showed remarkable decreases in SFR, AMY production, and MVD. However, transplantation of ADSCs alleviated irradiated PG morphology and function by preserving more functional acinar cells and increasing SFR and AMY production. In addition, greater MVD was observed in the ADSC-treated group than in the irradiated group. CONCLUSIONS: These results indicated that intraglandular transplantation of autologous ADSCs is an effective method to protect PGs against damage from irradiation in miniature pigs, which might have clinic application in the future.

Macrophages Undergo M1-to-M2 Transition in Adipose Tissue Regeneration in a Rat Tissue Engineering Model.

Macrophages are involved in the full processes of tissue healing or regeneration and play an important role in the regeneration of a variety of tissues. Although recent evidence suggests the role of different macrophage phenotypes in adipose tissue expansion, metabolism, and remodeling, the spectrum of macrophage phenotype in the adipose tissue engineering field remains unknown. The present study established a rat model of adipose tissue regeneration using a tissue engineering chamber. Macrophage phenotypes were assessed during the regenerative process in the model. Neo-adipose tissue was generated 6 weeks after implantation. Macrophages were obvious in the chamber constructs 3 days after implantation, peaked at day 7, and significantly decreased thereafter. At day 3, macrophages were predominantly M1 macrophages (CCR7+), and there were few M2 macrophages (CD206+). At day 7, the percentage of M2 macrophages significantly increased and remained stable at day 14. M2 macrophages became the predominant macrophage population at 42 days. Enzyme-linked immunosorbent assay demonstrated transition of cytokines from pro-inflammatory to anti-inflammatory, which was consistent with the transition of macrophage phenotype from M1 to M2. These results showed distinct transition of macrophage phenotypes from a pro-inflammatory M1 phenotype to an anti-inflammatory M2 in adipose tissue regeneration in our tissue engineering model. This study provides new insight into macrophage phenotype transition in the regeneration of adipose tissue.

Addition of Adipose-Derived Stem Cells to Mesenchymal Stem Cell Sheets Improves Bone Formation at an Ectopic Site.

To determine the effect of adipose-derived stem cells (ADSCs) added to bone marrow-derived mesenchymal stem cell (MSC) sheets on bone formation at an ectopic site. We isolated MSCs and ADSCs from the same rabbits. We then prepared MSC sheets for implantation with or without ADSCs subcutaneously in the backs of severe combined immunodeficiency (SCID) mice. We assessed bone formation at eight weeks after implantation by micro-computed tomography and histological analysis. In osteogenic medium, MSCs grew to form multilayer sheets containing many calcium nodules. MSC sheets without ADSCs formed bone-like tissue; although neo-bone and cartilage-like tissues were sparse and unevenly distributed by eight weeks after implantation. In comparison, MSC sheets with ADSCs promoted better bone regeneration as evidenced by the greater density of bone, increased mineral deposition, obvious formation of blood vessels, large number of interconnected ossified trabeculae and woven bone structures, and greater bone volume/total volume within the composite constructs. Our results indicate that although sheets of only MSCs have the potential to form tissue engineered bone at an ectopic site, the addition of ADSCs can significantly increase the osteogenic potential of MSC sheets. Thus, the combination of MSC sheets with ADSCs may be regarded as a promising therapeutic strategy to stimulate bone regeneration.

HIF-1α induced by hypoxic condition regulates Treg/Th17 axis polarization in chronic immune thrombocytopenia.

Immune thrombocytopenia (ITP) is an acquired immune disorder characterized by increased platelet destruction and reduced platelet (Plt) production. Hypoxia-inducible factor-1α (HIF-1α) have regulatory effects on Treg/Th17 axis balance and may represent relevant factors in the pathogenesis of ITP. Treg/Th17 ratio, serum levels and gene expression were investigated in new diagnosed ITP (NITP) and chronic ITP (CITP). The Treg/Th17 ratio obviously decreased in CITP (P = 0.001). The ratio of Treg/Th17 was correlated with the level of HIF-1α level both in mRNA (r = 0.49, P < 0.0001) and serum level (r = 0.50, P < 0.0001). However, none statistical upregulation of HIF-1α was observed in CITP. In vitro, There was significant polarization difference of Treg/Th17 axis (P = 0.042) and Foxp3-MFI/IL17-MFI (P = 0.0003) in hypoxic condition between NITP and CITP. These findings suggest that HIF-1α induced by hypoxia plays a crucial role in the chronicity of ITP by mediating the imbalance of the Treg/Th17 axis.

Spotlight on eltrombopag concentration in pediatric immune thrombocytopenia: A single-center observational study in China.

Importance: Eltrombopag has been recommended for pediatric immune thrombocytopenia (ITP). Response and adverse drug reactions (ADRs) varied widely between individuals, even at the same dose of eltrombopag. The appropriate eltrombopag concentration in ITP has not been reported. Objective: This study aims to explore the appropriate eltrombopag concentration in pediatric ITP. Methods: This was a single-center, prospective cohort study. Children diagnosed with refractory persistent/chronic ITP and platelet count < 30×109/L were treated with eltrombopag and followed up for at least 2 months. Concentration was detected by high-performance liquid chromatography-mass spectrometry at least 2 weeks after eltrombopag. The clinical characteristics-concentration, concentration-response, and concentration-ADRs were analyzed. Results: A total of 30 patients were enrolled, comprising 13 males and 17 females, with a median age of 72 (45‒94) months. The median dose and concentration were 1.39 (1.09‒1.56) mg/kg and 2.70 (2.25‒4.13) mg/L, respectively. Of the enrolled patients, 14 responded to treatment, whereas 16 did not. Additionally, five experienced adverse drug reactions. No linear correlation was observed between eltrombopag concentration and clinical characteristics. The concentration was lower in the response group than in the nonresponse group, but there was no significant difference (t = 0.755, P = 0.457). Patients who experienced ADRs had a higher concentration than those without ADRs (t = 2.538, P = 0.017). The area under the receiver operating characteristic curve of ADRs was 0.78 (95% confidence interval: 0.56‒1.00). Youden's index identified the cutoff point as 4.33 mg/L, with a sensitivity of 88% and a specificity of 60%. Logistic regression analysis demonstrated that a higher platelet count before eltrombopag predicted a favorable response. Interpretation: Eltrombopag proves efficacious and well-tolerated for treating pediatric ITP. However, prolonged and high-dose administration may increase the likelihood of ADRs. Thus, examining the appropriate eltrombopag concentration assists in directing individualized management of pediatric ITP.

Machine learning models developed and internally validated for predicting chronicity in pediatric immune thrombocytopenia.

BACKGROUND: Primary immune thrombocytopenia (ITP) in children is typically self-limiting; however, 20% to 30% of patients may experience prolonged thrombocytopenia lasting over a year. The challenge is predicting chronicity to ensure personalized treatment approaches. OBJECTIVES: To address this issue, we developed and internally validated 4 machine learning (ML) models using demographic and immunologic characteristics to predict the likelihood of chronicity. METHODS: The present study was conducted at Beijing Children's Hospital from June 2018 to December 2021, aiming to develop predictive models for determining the chronicity of pediatric ITP. Four ML models, based on a logistic regression classifier, random forest classifier, eXtreme Gradient Boosting (XGBoost), and support vector machine, were employed. These models used a set of 16 variables, including 14 immunologic and 2 demographic predictors. The performance evaluation criteria included prediction accuracy, precision, recall, F1 score, and area under the receiver operating characteristic curve (AUROC). RESULTS: Data were collected from 662 patients who were randomly assigned to either a training dataset or a testing dataset using a random number generator. Among them, 26.5% had chronic disease. All models performed well, with AUROC values ranging from 0.81 to 0.84, and XGBoost was selected for its highest AUROC score and interpretability in constructing the predictive model. Age, T helper 17, T helper 17-to-regulatory T cell ratio, T helper 1, and double-negative T cells were identified as significant predictors by the XGBoost algorithm. CONCLUSION: We developed a precise predictive model for chronicity in pediatric ITP using ML during the initial phase. The XGBoost model achieved high predictive accuracy by using individual patient clinical parameters and demonstrated commendable interpretability.

Effect of autologous lyophilized platelet­rich fibrin on the reconstruction of osteochondral defects in rabbits.

Osteochondral defects caused by degenerative diseases of joints, traumas and inflammation are important issues in clinical practice. Different types of autologous platelet concentrate (PCs) are used in bone and cartilage regeneration. The present study aimed to investigate the effect of lyophilized platelet-rich fibrin (L-PRF) on the repair of osteochondral defects in rabbits. L-PRF was first prepared from fresh PRF (F-PRF) through freeze-drying, and histological and microstructural observations were performed to compare the characteristics of L-PRF and F-PRF. Thereafter, these bioactive scaffolds were implanted into osteochondral defects surgically created in rabbits to assess their effects on tissue repair using micro-CT scanning, histological observations and the evaluation scoring method for cartilage repair established by the International Cartilage Repair Society (ICRS). L-PRF had a histological structure similar to F-PRF. At 16 weeks after implantation surgery, full-thickness osteochondral defects with a diameter of 5 mm and a depth of 4 mm were well-filled with newly regenerated tissues, exhibiting the simultaneous regeneration of avascular articular cartilage and well-vascularized subchondral bone, as proven through macroscopic and microscopic observations in PRF-treated groups compared with that in the untreated group. The application of L-PRF and F-PRF for osteochondral defects in rabbits contributed to massive host remodeling and reconstruction of osteochondral tissues, thus offering a prospective bioactive scaffold for the simultaneous reconstruction of articular cartilage and subchondral bone tissue.

The combination of a 3D-Printed porous Ti-6Al-4V alloy scaffold and stem cell sheet technology for the construction of biomimetic engineered bone at an ectopic site.

Cell sheet technology has been widely used in bone tissue engineering and regenerative medicine. However, controlling the shape and volume of large pieces of engineered bone tissue remains impossible without additional suitable scaffolds. Three-dimensional (3D) printed titanium (Ti) alloy scaffolds are mostly used as implant materials for repairing bone defects, but the unsatisfactory bioactivities of traditional Ti-based scaffolds severely limit their clinical applications. Herein, we hypothesize that the combination of bone marrow mesenchymal stem cell (BMSC) sheet technology and 3D porous Ti-6Al-4V (PT) alloy scaffolds could be used to fabricate biomimetic engineered bone. First, various concentrations of BMSCs were directly cocultured with PT scaffolds to obtain complexes of osteoblastic cell sheets and scaffolds. Then, as an experimental control, an osteoblastic BMSC sheet was prepared by continuous culturing under osteogenic conditions for 2 weeks without passaging and used to wrap the scaffolds. The BMSC sheet was composed of several layers of extracellular matrix (ECM) and a mass of BMSCs. The BMSCs exhibited excellent adherent, proliferative and osteogenic potential when cocultured with PT scaffolds, which may be attributed to the ability of the 3D microstructure of scaffolds to facilitate the biological behaviors of cells, as confirmed by the in vitro results. Moreover, the presence of BMSCs and ECM increased the angiogenic potential of PT scaffolds by the secretion of VEGF. Micro-CT and histological analysis confirmed the in vivo formation of biomimetic engineered bone when the complex of cocultured BMSCs and PT scaffolds and the scaffolds wrapped by prepared BMSC sheets were implanted subcutaneously into nude mice. Therefore, the combination of BMSC sheet technology and 3D-printed PT scaffolds could be used to construct customized biomimetic engineered bone, offering a novel and promising strategy for the precise repair of bone defects.

Identification of Potential Genetic Biomarkers and Target Genes of Peri-Implantitis Using Bioinformatics Tools.

OBJECTIVES: To investigate potential genetic biomarkers of peri-implantitis and target genes for the therapy of peri-implantitis by bioinformatics analysis of publicly available data. METHODS: The GSE33774 microarray dataset was downloaded from the Gene Expression Omnibus (GEO). The differentially expressed genes (DEGs) between peri-implantitis and healthy gingival tissues were identified using the GEO2R tool. GO enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using the DAVID database and the Metascape tool, and the results were expressed as a bubble diagram. The protein-protein interaction network of DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) and visualized using Cytoscape. The hub genes were screened by the cytoHubba plugin of Cytoscape. The potential target genes associated with peri-implantitis were obtained from the DisGeNET database and the Open Targets Platform. The intersecting genes were identified using the Venn diagram web tool. RESULTS: Between the peri-implantitis group and the healthy group, 205 DEGs were investigated including 140 upregulated genes and 65 downregulated genes. These DEGs were mainly enriched in functions such as the immune response, inflammatory response, cell adhesion, receptor activity, and protease binding. The results of KEGG pathway enrichment analysis revealed that DEGs were mainly involved in the cytokine-cytokine receptor interaction, pathways in cancer, and the PI3K-Akt signaling pathway. The intersecting genes, including IL6, TLR4, FN1, IL1ß, CXCL8, MMP9, and SPP1, were revealed as potential genetic biomarkers and target genes of peri-implantitis. CONCLUSIONS: This study provides supportive evidence that IL6, TLR4, FN1, IL1ß, CXCL8, MMP9, and SPP1 might be used as potential target biomarkers for peri-implantitis which may provide further therapeutic potentials for peri-implantitis.

Osteogenic and angiogenic lineage differentiated adipose-derived stem cells for bone regeneration of calvarial defects in rabbits.

Cell sheet techniques are widely used in bone engineering. However, vascularization remains a challenge in fabricating vascularized engineered bone. The goal of this study was to induce adipose-derived stem cell (ADSC) osteogenic and angiogenic lineage differentiation and investigate the use of bidiretionally differentiated ADSCs for bone regeneration. ADSCs were cultured to form an osteogenic cell sheet. Other ADSCs were induced to differentiate into endothelial progenitor cells (EPCs), which were identified and characterized by morphological observation and CD31 immunofluorescent staining. Then, the ADSC sheet-EPC complexes were implanted subcutaneously into nude mice, while ADSC sheets alone were implanted as a control. After 8 weeks of transplantation, microcomputed tomography (micro-CT) and histological observation were used to assess bone formation. We then implanted the complexes in calvarial defects in rabbits and assessed bone repair by micro-CT and histological analysis. The ADSC sheets consisted of multiple layers of cells and extracellular matrix. The obtained EPCs formed capillary-like structures and expressed the specific antigen marker CD31. The osteogenic ADSC sheet-EPC complexes formed dense and well-vascularized new bone tissue at 8 weeks after implantation. Bone density was significantly lower in the control group than in the complex group (p < .05). In addition, the reconstruction of calvarial defects in rabbits in complex group was obviously greater than that in the control group (p < .05). These results suggested that the approach of engineering bone tissue with bidiretionally differentiated ADSCs enabled bone regeneration, thus offering a promising strategy for repairing bone defects.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis.

Long non-coding RNAs (lncRNAs) can potentially regulate all aspects of cellular activity including differentiation and development, metabolism, proliferation, apoptosis, and activation, and benefited from advances in transcriptomic and genomic research techniques and database management technologies, its functions and mechanisms in physiological and pathological states have been widely reported. Liver fibrosis is typically characterized by a reversible wound healing response, often accompanied by an excessive accumulation of extracellular matrix. In recent years, a range of lncRNAs have been investigated and found to be involved in several cellular-level regulatory processes as competing endogenous RNAs (ceRNAs) that play an important role in the development of liver fibrosis. A variety of lncRNAs have also been shown to contribute to the altered cell cycle, proliferation profile associated with the accelerated development of liver fibrosis. This review aims to discuss the functions and mechanisms of lncRNAs in the development and regression of liver fibrosis, to explore the major lncRNAs involved in the signaling pathways regulating liver fibrosis, to elucidate the mechanisms mediated by lncRNA dysregulation and to provide new diagnostic and therapeutic strategies for liver fibrosis.