Low-Temperature Deposited Amorphous Poly(aryl ether ketone) Hierarchically Porous Scaffolds with Strontium-Doped Mineralized Coating for Bone Defect Repair.

In recent years, the demand for clinical bone grafting has increased. As a new solution for orthopedic implants, polyether ether ketone (PEEK, crystalline PAEK) has excellent comprehensive performance and has been practically applied in clinic. In this research, a noteworthy elevated scheme to enhance the performance of PEEK scaffolds was presented. The amorphous aggregated poly (aryl ether ketone) (PAEK) resin was prepared as the matrix material, which maintained high mechanical strength and could be processed through solution. So, the tissue engineering scaffolds with multilevel pores could be printed by low-temperature deposited manufacturing (LDM) to improve biologically inert scaffolds with smooth surfaces. Also, the feature of PAEK's solution processing is profitable to uniformly add the functional components for bone repair. Ultimately, A system of orthopedic implantable PAEK material based on intermolecular interactions, surface topology, and surface modification was established. The specific steps include synthesizing PAEK that contain polar carboxyl structures, preparing bioinks and fabricating scaffolds by LDM, preparation of scaffolds with strontium-doped mineralized coatings, evaluation of their osteogenic properties in vitro and in vivo, and investigation on the effect and mechanism of scaffolds in promoting osteogenic differentiation. This work provides an upgraded system of PAEK implantable materials for clinical application. This article is protected by copyright. All rights reserved.

Multivariate analyses on male factors and construction of a nomogram for predicting low in vitro fertilization rate.

Low fertilization rate (LFR) and total fertilization failure (TFF) are often encountered in routine in vitro fertilization (IVF) procedure. To solve this problem, multivariate analyses on the relationship between male factors and in vitro fertilization rate were performed, and a nomogram for prediction of LFR was constructed. This retrospective study contained 2011 couples who received IVF treatment from January 2017 to December 2021. Man factors and in vitro fertilization rate were collected. Among these couples, 1347 cases had in vitro fertilization rates ≥30 % (control group), and 664 cases had in vitro fertilization rates <30 % (LFR group). Univariate analyses of male factors found that between the two groups there were significant differences (p < 0.05) in sperm progressive motility (SPR), sperm concentration (SC), total sperm number, normal sperm morphology rate (NSMR), DNA fragmentation index (DFI), sperm acrosin activity (SAA) and the clinical diagnosis of primary or secondary infertility. Multivariate logistic regression analyses showed that SPR, SAA, and SC were independent risk factors for LFR. An algorithm and a correspondent nomogram for predicting high LFR risk were constructed using data from the training cohort. The LFR nomogram exhibited an excellent discrimination power and a high fitting degree in both the training cohort (AUC = 0.90, 95 % CI: 0.88-0.92), (H-L: x2 = 5.43, p = 0.71) and validation cohort (AUC = 0.89, 95 % CI:0.87-0.92), (H-L: x2 = 7.85, p = 0.45), respectively. The decision curve analysis (DCA) demonstrated a high efficiency of the LFR nomogram for clinical utility. SPR, SAA, and SC are independent risk factors for LFR. The LFR nomogram established based on these factors could be a useful tool to predict high risk of LFR, and patients with high risk of LFR can be guided to direct ICSI procedure. Clinical application of the LFR nomogram may increase the in vitro fertilization rate by facilitating the decision making in IVF service.

Strategies to improve the performance of polyetheretherketone (PEEK) as orthopedic implants: from surface modification to addition of bioactive materials.

Polyetheretherketone (PEEK), as a high-performance polymer, is widely used for bone defect repair due to its homogeneous modulus of elasticity of human bone, good biocompatibility, excellent chemical stability and projectability. However, the highly hydrophobic surface of PEEK is biologically inert, which makes it difficult for cells and proteins to attach, and is accompanied by the development of infections that ultimately lead to failure of PEEK implants. In order to further enhance the potential of PEEK as an orthopedic implant, researchers have explored modification methods such as surface modification by physical and chemical means and the addition of bioactive substances to PEEK-based materials to enhance the mechanical properties, osteogenic activity and antimicrobial properties of PEEK. However, these current modification methods still have obvious shortcomings in terms of cost, maneuverability, stability and cytotoxicity, which still need to be explored by researchers. This paper reviews some of the modification methods that have been used to improve the performance of PEEK over the last three years in anticipation of the need for researchers to design PEEK orthopedic implants that better meet clinical needs.

Comparisons of the analgesic effect of different pulsed radiofrequency targets in SNI-induced neuropathic pain.

An injury of the peripheral nerve may lead to neuropathic pain, which could be treated with pulsed radiofrequency to the dorsal root ganglion (DRG) or peripheral nerve [the nerve trunk (NT) or proximal to the injury site (NI)]. However, it is not clear whether there is any difference in analgesic effect or maintenance among the three targets. PRF was applied to the ipsilateral L5 DRG, peripheral nerve (NT or NI) 5 days after spared nerve injury (SNI). Triptolide (10 µg/kg) or vehicle was intrathecally administered 5 days after SNI for 3 days. Mechanical withdrawal thresholds were tested after treatment at different time points. Furthermore, microglia and the P2X7 receptor (P2X7R) in the ipsilateral spinal cord were measured with immunofluorescence and western blotting, respectively. PRF + NI exerted a more remarkable analgesic effect than PRF + DRG and PRF + NT at the early stage, but PRF + DRG had a stronger analgesic effect than PRF + NI and PRF + NT at the end of our study. In addition, PRF + DRG showed no significant difference from intrathecal administration of triptolide. Moreover, SNI-induced microglia activation and upregulation of P2X7R in spinal dorsal horn could be markedly inhibited by PRF + DRG. The results suggest that the analgesic effect of PRF + DRG increased with time whereas the other two not and microglia and P2X7R in the ipsilateral spinal dorsal horn may be involved in the process.

Low-temperature deposition manufacturing technology: a novel 3D printing method for bone scaffolds.

The application of three-dimensional printing technology in the medical field has great potential for bone defect repair, especially personalized and biological repair. As a green manufacturing process that does not involve liquefication through heating, low-temperature deposition manufacturing (LDM) is a promising type of rapid prototyping manufacturing and has been widely used to fabricate scaffolds in bone tissue engineering. The scaffolds fabricated by LDM have a multi-scale controllable pore structure and interconnected micropores, which are beneficial for the repair of bone defects. At the same time, different types of cells or bioactive factor can be integrated into three-dimensional structural scaffolds through LDM. Herein, we introduced LDM technology and summarize its applications in bone tissue engineering. We divide the scaffolds into four categories according to the skeleton materials and discuss the performance and limitations of the scaffolds. The ideas presented in this review have prospects in the development and application of LDM scaffolds.

An atypical erectile dysfunction patient with infertility treated with penile prosthesis implantation and testicular epididymal sperm aspiration (TESA)-intracytoplasmic sperm injection (ICSI): A case report.

RATIONALE: Erectile dysfunction (ED) is common in middle-aged and elderly men, affecting more than 100 million males worldwide. Most ED cases can be attributed to organic and/or psychological factors. Here we report an atypical ED case with no clear manifestation fitting the diagnosis for recognized types of ED. PATIENT CONCERNS: The 35-year-old male is unable to have normal erection since puberty, and unable to complete intercourse with his wife. He had no history of trauma, surgery or psychiatric/psychological disease. The patient has a normal male karyotype. There is no significant finding in physical examination, nocturnal penile tumescence test, and ultrasound measurement of penis vascular functions. The serum levels of major hormones are all in normal ranges. DIAGNOSES: Atypical ED, psychogenic ED not excluded; infertility. INTERVENTIONS: Oral phosphodiesterase inhibitors Tadalafil (20 mg, BIW) or Sildenafil (50 mg, BIW) had no effect in this patient. Penile prosthesis implantation helped the patient to acquire normal sexual life, but did solve the ejaculation failure and infertility. Motile sperms were obtained by testicular epididymal sperm aspiration under the guidance of ultrasound, and intracytoplasmic sperm injection was performed with occytes retrieved from his wife. OUTCOMES: The patient sexual life was significantly improved after penile prosthesis implantation; the patient wife is currently in the first trimester of pregnancy as the result of in vitro fertilization. CONCLUSIONS: The no response to phosphodiesterase type 5 inhibitors (PDE5) treatment may suggest an impediment of PDE5-related pharmacological pathways or the presence of defect/injury in the neural system. This special case raises a question if some patients with persistent ED may have similar manifestations and can be treated with the same procedures.

3D Printing and Performance Study of Porous Artificial Bone Based on HA-ZrO2-PVA Composites.

An ideal artificial bone implant should have similar mechanical properties and biocompatibility to natural bone, as well as an internal structure that facilitates stomatal penetration. In this work, 3D printing was used to fabricate and investigate artificial bone composites based on HA-ZrO2-PVA. The composites were proportionally configured using zirconia (ZrO2), hydroxyapatite (HA) and polyvinyl alcohol (PVA), where the ZrO2 played a toughening role and PVA solution served as a binder. In order to obtain the optimal 3D printing process parameters for the composites, a theoretical model of the extrusion process of the composites was first established, followed by the optimization of various parameters including the spray head internal diameter, extrusion pressure, extrusion speed, and extrusion line width. The results showed that, at the optimum parameters of a spray head diameter of 0.2 mm, extrusion pressure values ranging from 1-3 bar, a line spacing of 0.8-1.5 mm, and a spray head displacement range of 8-10 mm/s, a better structure of biological bone scaffolds could be obtained. The mechanical tests performed on the scaffolds showed that the elastic modulus of the artificial bone scaffolds reached about 174 MPa, which fulfilled the biomechanical requirements of human bone. According to scanning electron microscope observation of the scaffold sample, the porosity of the scaffold sample was close to 65%, which can well promote the growth of chondrocytes and angiogenesis. In addition, c5.18 chondrocytes were used to verify the biocompatibility of the composite materials, and the cell proliferation was increased by 100% when compared with that of the control group. The results showed that the composite has good biocompatibility.

Low-Temperature Printed Hierarchically Porous Induced-Biomineralization Polyaryletherketone Scaffold for Bone Tissue Engineering.

Polyetheretherketone (PEEK) as a popular orthopaedic implant is usually fabricated into a hierarchically porous structure for improving osteogenic activity. However, the applications are limited due to the excessively high processing temperature and uncontrollably tedious modification routes. Here, an amorphous polyaryletherketone with carboxyl groups (PAEK-COOH) is synthesized and fabricated to the hierarchically controllable porous scaffolds via a low-temperature 3D-printing process. The prepared PAEK-COOH scaffolds present controllable porous structures ranging from nano- to micro-scale, and their mechanical strengths are comparable to that of trabecular bone. More importantly, the in vitro experiments show that the nanoporous surface is conducive to promoting cellular adhesion, and carboxyl groups can induce hydroxyapatite mineralization via electrostatic interaction. The in vivo experiments demonstrate that the PAEK-COOH scaffolds offer much better osseointegration without additional active ingredients, compared to that of PEEK. Therefore, this work will not only develop a promising candidate for bone tissue engineering, but provide a viable method to design PAEK biomaterials.

Synthesis of thermally robust benzimidazolone-based wholly aromatic polyketones.

A series of wholly aromatic polyketones bearing benzimidazolone moieties (PK-BI) were synthesized via N-C coupling polycondensation. Calcium carbonate coupled with potassium carbonate was used for the first time to achieve a high molecular weight, with T g of the polymer as high as 299 °C. The polymer structure was confirmed by solid state 13C NMR and FT-IR. The thermal stability of wholly aromatic polyketones with a benzimidazolone unit in the main chain was significantly improved, being higher than those of PEEKs and other amorphous PAEKs, proved by thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) analysis. The degradation activation energy (E k) values estimated by Flynn-Wall-Ozawa (FWO) and Kissinger methods were 260.33 kJ mol-1 and 282.57 kJ mol-1, respectively, which are higher than those of PEEKs.

MicroRNA-490-3p suppresses the proliferation and invasion of hepatocellular carcinoma cells via targeting TMOD3.

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver. It has been reported that microRNAs (miRs) play important roles in the progression and development of HCC. The expression of miR-490-3p has been shown to be downregulated in HCC tissues. Therefore, the present study aimed to investigate the effects of miR-490-3p on HCC cells and the underlying mechanism. Cell Counting Kit-8, flow cytometry, and Transwell migration and invasion assays were performed to determine the viability, apoptosis, migration and invasion of HCC cells, respectively. Furthermore, a luciferase activity assay was used to verify the association between miR-490-3p and its predicted target tropomodulin 3 (TMOD3). In addition, the protein levels of Bax, Bcl-2, cleaved caspase-3, TMOD3, phosphorylated (p)-p38 and p-ERK in HCC cells were detected using western blot analysis. The results demonstrated that the overexpression of miR-490-3p via transfection with miR-490-3p mimics significantly inhibited the proliferation of Huh-7 and HEP 3B2.1-7 cells. In addition, overexpression of miR-490-3p markedly suppressed the migration and invasion abilities of Huh-7 cells. miR-490-3p mimics significantly induced liver cancer cell apoptosis via upregulating Bax and cleaved caspase-3 and downregulating anti-apoptotic protein Bcl-2. Additionally, a luciferase activity assay indicated that TMOD3 is a downstream target gene of miR-490-3p. The protein levels of TMOD3, p-p38 and p-ERK were significantly downregulated in Huh-7 cells following transfection with miR-490-3p mimics, and the overexpression of TMOD3 attenuated these effects. In conclusion, the aforementioned results suggest that the overexpression of miR-490-3p inhibited the proliferation and invasion of HCC cells by targeting TMOD3. Therefore, the miR-490-3p/TMOD3 axis may be a potent target for the treatment of HCC.

TAZ is overexpressed in prostate cancers and regulates the proliferation, migration and apoptosis of prostate cancer PC3 cells.

TAZ (transcriptional coactivator with PDZ­binding motif), which is also known as WW domain­containing transcription regulator 1 (WWTR1), a downstream effector of the Hippo pathway, has been reported to regulate cancer cell proliferation, migration and apoptosis by acting as a transcriptional coactivator. However, the function of TAZ in prostate cancer cells has not been investigated. In the present study, TAZ expression in prostate cancer (PCa) and benign prostatic hyperplasia tissues, PCa cell lines, and normal prostate epithelial cells was determined with the use of immunohistochemistry. TAZ was knocked down by shRNA in the PC3 cells, a prostate cancer cell line, and cell viability and migration assays were performed to determine the biological functions of TAZ. A mouse subcutaneous xenograft model was used to determine the in vivo effects of TAZ knockdown on tumor growth. We demonstrated that TAZ is overexpressed in PCa tissues, and the expression levels were found to be positively correlated with the Gleason scores of cancer grade. Moreover, TAZ knockdown inhibited PC3 cell proliferation, reduced cell migration, and induced apoptosis. Further experiments demonstrated that TAZ knockdown may lead to PC3 cell apoptosis through the exogenous apoptotic pathway by inducing the expression and cleavage of caspase­4 and ­7. In the tumor xenograft model, TAZ knockdown led to a decreased tumor growth rate. Taken together, the experimental results indicate that TAZ plays a significant role in the proliferation, migration and apoptosis of prostate cancer cells. TAZ could be a useful biomarker for PCa diagnosis/prognosis, and it could be a potential target for the treatment of prostate cancers.

A Novel Acetylene-Functional/Silicon-Containing Benzoxazine Resin: Preparation, Curing Kinetics and Thermal Properties.

Benzoxazine resin has been paid more attention in the fields of aviation, electronics, automobiles and new energy industries because of its excellent comprehensive performance. Further application is limited, however, by shortcomings such as high brittleness and high curing temperature. Furthermore, higher thermal stability is imperiously demanded in special areas. Incorporating both an acetylene group and silicon into the benzoxazine monomer is a promising possible solution to improve the curing processability, thermal properties and toughness of benzoxazine. In this paper, an acetylene-functional/silicon-containing benzoxazine monomer was prepared by two-step synthesis, and acetylene-functional benzoxazine was also prepared as a comparison. FTIR and 1H NMR confirmed the molecular structure of acetylene-functional/silicon-containing benzoxazine. Differential scanning calorimetry (DSC) analysis showed that the initial and peak degradation temperatures of acetylene-functional/silicon-containing benzoxazine were decreased by 21 °C and 18 °C compared with acetylene-functional benzoxazine, respectively. The apparent activation energy of the curing reaction of acetylene-functional/silicon-containing benzoxazine was 83.1 kJ/mol, which was slightly lower than acetylene-functional benzoxazine (84.7 kJ/mol). TGA results showed that the acetylene-functional/silicon-containing benzoxazine had a higher thermal stability than acetylene-functional benzoxazine. The temperatures of 5% weight loss of acetylene-functional/silicon-containing benzoxazine were 380 °C in nitrogen and 485 °C in air, and the char yield at 1000 °C was 80% in nitrogen and 21% in air, respectively. The results of mechanical properties showed that the impact strength of acetylene-functional/silicon-containing benzoxazine was higher than acetylene-functional benzoxazine by 35.4%. The tensile and flexural strengths of acetylene-functional/silicon-containing benzoxazine were slightly higher than that of acetylene-functional benzoxazine.

A Novel Zirconium Modified Arylacetylene Resin: Preparation, Thermal Properties and Ceramifiable Mechanism.

With the rapid development of thermal protection systems for the aerospace industry and power electronics, polyarylacetylene (PAA) resin plays an important role because of its good mechanical properties, high glass transition temperature (Tg), low water absorption, high char yield (Yc), and the fact that there is no byproduct released in the curing process. In order to further improve the thermal property of PAA based FRP for the thermal protection field, the introduction of a zirconium element into arylacetylene is promising. In this paper, zirconium modified arylacetylene (ZAA) resin was prepared by two-step synthesis. The FTIR analysis characterized its molecular structure and confirmed the products. The viscosity of ZAA was about 6.5 Pa·s when the temperature was above 120 °C. The DSC analysis showed that the ZAA had a low curing temperature, and its apparent activation energy was 103.86 kJ/mol in the Kissinger method and 106.46 kJ/mol in the Ozawa method. The dielectric constant at 1 MHz of poly(zirconium modified arylacetylene) (PZAA) was 3.4. The TG analysis showed that the temperatures of a weight loss of 5% (Td5) and char yield (Yc) at 800 °C of PZAA were 407.5 °C and 61.4%, respectively. The XRD results showed the presence of SiO2 and ZrO2 in the PZAA residue after ablation. The XRF results showed that the contents of SiO2 and ZrO2 in PZAA residual after ablation were, respectively, 15.3% and 12.4%. The SEM showed that the surface of PZAA after ablation had been covered with a dense and rigid ceramic phase composed of ZrO2 and SiO2. Therefore, the introduction of Zr into arylacetylene greatly improved the densification of the surface after ablation, and improved the heat resistant property.

Effects of Zirconium Silicide on the Vulcanization, Mechanical and Ablation Resistance Properties of Ceramifiable Silicone Rubber Composites.

Ceramifiable silicone rubber composites play important roles in the field of thermal protection systems (TPS) for rocket motor cases due to their advantages. Ceramifiable silicone rubber composites filled with different contents of ZrSi2 were prepared in this paper. The fffects of ZrSi2 on the vulcanization, mechanical and ablation resistance properties of the composites were also investigated. The results showed that the introduction of ZrSi2 decreased the vulcanization time of silicone rubber. FTIR spectra showed that ZrSi2 did not participate in reactions of the functional groups of silicone rubber. With the increasing content of ZrSi2, the tensile strength increased first and then decreased. The elongation at break decreased and the permanent deformation increased gradually. The thermal conductivity of the composite increased from 0.553 W/(m·K) to 0.694 W/(m·K) as the content of the ZrSi2 increased from 0 to 40 phr. In addition, the thermal conductivity of the composite decreased with the increase of temperature. Moreover, thermal analysis showed that the addition of ZrSi2 increased the initial decomposition temperature of the composite, but had little effect on the peak decomposition temperature in nitrogen. However, the thermal decomposition temperature of the composite in air was lower than that in nitrogen. The addition of ZrSi2 decreased the linear and mass ablation rate, which improved the ablative resistance of the composite. With the ZrSi2 content of 30 phr, the linear and mass ablation rate were 0.041 mm/s and 0.029 g/s, decreasing by 57.5% and 46.3% compared with the composite without ZrSi2, respectively. Consequently, the ceramifiable silicone rubber composite filled with ZrSi2 is very promising for TPS.

Preparation of Amorphous Poly(aryl ether nitrile ketone) and Its Composites with Nano Hydroxyapatite for 3D Artificial Bone Printing.

PEEK had been used to fabricate artificial bones by 3D printing widely, but it expressed unsatisfactory interlayer performance of 3D printing and weak compatibility with nano hydroxyapatite(nHA) due to the limits of molecular structures. Here an amorphous poly(aryl ether ketone) for 3D bone printing, PEK-CN, was designed and synthesized via nucleophilic substitution from 4,4'-difluorobenzophenone, phenolphthalein and 2,6-dichlorobenzonitrile, which possessed much stronger interlayer strength due to van der Waals force between polar groups(-CNs). Specifically, the stronger interlayer strength resulted in lower porosity(3% with 100% infill rate) and more comparable mechanical properties(the maximum tensile strength was ∼110 MPa) to cortical bone. Importantly, PEK-CN had passed in vitro cytotoxicity testing and samples of human mandible and maxillary bones based on PEK-CN were printed by fused deposition modeling(FDM) successfully. Moreover, PEK-CN/nHA composites were obtained to enhance bioactivity of resin, and PEK-CN without limits of crystal lattices expressed excellent compatibility with nano hydroxyapatite. Our work provided a high performance resin for 3D bone printing, which would bring better solutions for artificial bone materials.

Improved Processing and Properties for Polyphenylene Oxide Modified by Diallyl Orthophthalate Prepolymer.

Diallyl orthophthalate (DAOP) prepolymer was investigated as a reactive plasticizer to improve the processability of thermoplastics. The rheology of blends of DAOP prepolymer initiated by 2,3-dimethyl-2,3-diphenylbutane (DMDPB) and polyphenylene oxide (PPO) was monitored during the curing process, and their thermal properties and morphology in separated phases were also studied. Differential scanning calorimetry (DSC) results showed that the cure degree of the reactively plasticized DAOP prepolymer was reduced with increasing PPO due to the dilution effect. The increasing amount of the DAOP prepolymer led to a gradual decrease in the viscosity of the blends and the rheology behavior was consistent with the chemical gelation of DAOP prepolymer in blends. This indicated that the addition of the DAOP prepolymer effectively improved processability. The phase separation occurring during curing of the blend and the transition from the static to dynamic mode significantly influences the development of the morphology of the blend corresponding to limited evolution of the conversion around the gel point.

Morroniside protects against chronic atrophic gastritis in rat via inhibiting inflammation and apoptosis.

The aim of our study was to investigate the therapeutic efficacy of Morroniside (MR) in a chronic atrophic gastritis (CAG) rat model and its underlying mechanisms. Male Wistar rats were employed to induce CAG model. All animals were divided into six groups: control, model (CAG), positive (Vitacoenzyme tablets), MR low, middle and high three doses groups. Histopathology observation of gastric tissues was detected by hematoxylin and eosin (H&E) staining. The levels of gastrointestinal hormones and inflammatory factors in serum were measured by Enzyme-linked immunosorbent assay (ELISA). Apoptosis of gastric mucosa cell was detected using Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) assay. Protein expressions were evaluated by Western blotting. Obvious pathological injury and in the CAG model group were observed, which was improved after treatment with MR. The contents of serum gastrin (GAS) was increased whereas motilin (MTL) was decreased in a dose-dependent manner after MR treatment. MR markedly attenuated the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1 beta (IL-1ß). Moreover, MR inhibited apoptosis of gastric mucosal cell as presented by TUNEL, coupled with an upregulation in Bcl-2 expression and a downregulation in Bax, cleaved caspase-3 and cleaved caspase-9 expression. Furthermore, the expression levels of phospho-NF-κB p65 (p-NF-κB p65) and p-IKKα/ß proteins were reduced accompanied by an increase in IκB-α expression in the MR-treated groups. The study demonstrated that MR is able to protect against CAG via inhibiting inflammation and apoptosis, which might provide a stronger theoretical basis for the treatment of CAG.

A candidate DNA vaccine encoding a fusion protein of porcine complement C3d-P28 and ORF2 of porcine circovirus type 2 induces cross-protective immunity against PCV2b and PCV2d in pigs.

BACKGROUND: Porcine circovirus type 2 (PCV2) is an economically important viral pathogen for swine industry worldwide. However, current PCV2 vaccines provide incomplete protection against the PCV2d, which has recently emerged as the predominant pathogenic form of PCV2. METHODS: To develop a novel DNA vaccine with high efficacy against PCV2d virus, we fused the ORF2 of PCV2d to three copies of the minimum-binding domain of the complement C3 cascade terminal component, C3d-P28. Expression of ORF2 alone (pVO) or fused C3d-P28 (pVOC3) were verified by immunofluorescent assay. Vaccine efficacy was tested by measured the DNA copy and T and B cell immune response. RESULTS: Vaccination with pVOC3 reduced the levels of PCV2 genomic DNA after pigs were infected with either PCV2b or PCV2d genotypes, produced potent antibodies against PCV2, and stimulated PCV2-specific interferon-γ secreting cells. CONCLUSION: Results suggested pVOC3 would be a safe and effective DNA vaccine to confer cross-protection against both PCV2b and PCV2d genotypes in pigs.