Ferromagnetic-Based Charge-Accumulation Triboelectric Nanogenerator With Ultrahigh Surface Charge Density.

An encouraging micro-energy harvesting technology, the triboelectric nanogenerator (TENG), has been proven to transfer ambient environmental micro-energy into electricity, but a low surface charge density results in low performance and limits the practical application of TENG. Here, a ferromagnetic-based charge-accumulation TENG (FC-TENG) is proposed with ultrahigh surface charge density and performances. The FC-TENG introduces a ferromagnetic media to enhance the output charge by magnetization effect. Meanwhile, the charge can also be continuously accumulated by the charge pump effects. Based on these two effects, an ultra-high surface charge density of 2.85 mC m-2 is obtained under ambient atmospheric conditions using an ultra-thin PET film (3 µm) and deposited Permalloy ferromagnetic electrodes. Meanwhile, the surface charge density of the FC-TENG can always maintain more than 1.5 mC m-2 , even if the relative humidity arrives at 90%. This work provides a prospective technical mode to enhance the surface charge density of TENG, which would shed a new insight and guidance on the high-performance TENG for various environmental conditions such as the ocean, industrial manufacturing, aerospace, and rail traffic.

Optimal bright multimode quantum squeezing via multi-seeding energy-level cascaded four-wave mixing.

Quantum Squeezing is one of the most important quantum resources in quantum optics and quantum information. In particular, multimode quantum squeezing, with ultra-low quantum fluctuations and quantum correlations amongst many optical modes, is essential for realizing multipartite entanglement and quantum precision measurements. In this paper, we propose an all-optically controlled scheme to generate three-mode bright quantum correlated beams from energy-level cascaded four-wave mixing (ELC-FWM). By using a linear modes transform approach, the input-output relation and the covariance matrix of the produced states are obtained. Moreover, single-, double- and triple-seeding conditions are investigated to measure the quantum squeezing properties. We find that various permutations of two- and three-mode quadrature squeezing can be generated and optimized to reach the corresponding limit, via only modulating the ratio of the multiple seeds, without need of any post-operating linear optics, e.g., beam splitters. Such weak seeding light controlled scheme suggests the modulation and the optimization of multimode quantum states might be operated at photons-level, providing a reconfigurable and integrated strategy for complex quantum information processing and quantum metrology.

Triboelectric Nanogenerators as Active Tactile Stimulators for Multifunctional Sensing and Artificial Synapses.

The wearable tactile sensors have attracted great attention in the fields of intelligent robots, healthcare monitors and human-machine interactions. To create active tactile sensors that can directly generate electrical signals in response to stimuli from the surrounding environment is of great significance. Triboelectric nanogenerators (TENGs) have the advantages of high sensitivity, fast response speed and low cost that can convert any type of mechanical motion in the surrounding environment into electrical signals, which provides an effective strategy to design the self-powered active tactile sensors. Here, an overview of the development in TENGs as tactile stimulators for multifunctional sensing and artificial synapses is systematically introduced. Firstly, the applications of TENGs as tactile stimulators in pressure, temperature, proximity sensing, and object recognition are introduced in detail. Then, the research progress of TENGs as tactile stimulators for artificial synapses is emphatically introduced, which is mainly reflected in the electrolyte-gate synaptic transistors, optoelectronic synaptic transistors, floating-gate synaptic transistors, reduced graphene oxides-based artificial synapse, and integrated circuit-based artificial synapse and nervous systems. Finally, the challenges of TENGs as tactile stimulators for multifunctional sensing and artificial synapses in practical applications are summarized, and the future development prospects are expected.

Recent Progress of Switching Power Management for Triboelectric Nanogenerators.

Based on the coupling effect of contact electrification and electrostatic induction, the triboelectric nanogenerator (TENG) as an emerging energy technology can effectively harvest mechanical energy from the ambient environment. However, due to its inherent property of large impedance, the TENG shows high voltage, low current and limited output power, which cannot satisfy the stable power supply requirements of conventional electronics. As the interface unit between the TENG and load devices, the power management circuit can perform significant functions of voltage and impedance conversion for efficient energy supply and storage. Here, a review of the recent progress of switching power management for TENGs is introduced. Firstly, the fundamentals of the TENG are briefly introduced. Secondly, according to the switch types, the existing power management methods are summarized and divided into four categories: travel switch, voltage trigger switch, transistor switch of discrete components and integrated circuit switch. The switch structure and power management principle of each type are reviewed in detail. Finally, the advantages and drawbacks of various switching power management circuits for TENGs are systematically summarized, and the challenges and development of further research are prospected.

Effect of precision air supply cooling system with different cooling air speed on reproductive performance, stress status, immunoglobulin and fecal microbiota of lactating sows.

This study investigated the precision air supply cooling system with different cooling air speed on reproductive performance, stress status, immunity and intestinal microbiota of sows. A total of 36 sows were randomly assigned into three groups: control group (CON, n = 12) without cooling system, low cooling air speed (2.24 ± 0.11 m/s) group (LCAS, n = 12) with precision air supply cooling system, high cooling air speed (3.33 ± 0.11 m/s) group (HCAS, n = 12) with precision air supply cooling system. The average daily ambient temperature and relative humidity in experimental farrowing rooms were 28 °C-32 °C and 65%-90%, respectively, during daytime (8:00-20:00). The reproductive performance, respiratory rate (RR), body surface temperature (BST), rectal temperature (RT) salivary parameters and fecal microbiota of lactating sows were measured. The results showed that compared with CON group, average daily feed intake of sows and average daily gain of piglets were increased (P < 0.05) in LCAS and HCAS groups. The RR, BST and RT were decreased (P < 0.05) in LCAS and HCAS groups in wk 1 before parturition and wk 2 after parturition. The salivary cortisol and alpha amylase level of LCAS and HCAS sows were decreased (P < 0.05) on d 14 after parturition, while the salivary immunoglobulin A and immunoglobulin G level of LCAS and HCAS sows were increased (P < 0.05) on d 7 after parturition. The LCAS and HCAS sows showed higher relative abundance of Clostridium_sensu_stricto_1 in feces, which was positively associated with immunoglobulin A (P < 0.01). In conclusion, both low and high cooling air speed improved reproductive performance, alleviated stress status, and enhanced salivary immunoglobulins and beneficial fecal microbiota community in lactating sows, which indicated that precision air supply cooling system could be an effective cooling strategy for lactating sows in high ambient temperature.

Localized gap modes of coherently trapped atoms in an optical lattice.

We theoretically investigate one-dimensional localized gap modes in a coherent atomic gas where an optical lattice is formed by a pair of counterpropagating far-detuned Stark laser fields. The atomic ensembles under study emerge as Λ-type three-level configuration accompanying the effect of electromagnetically induced transparency (EIT). Based on Maxwell-Bloch equations and the multiple scales method, we derive a nonlinear equation governing the spatial-temporal evolution of the probe-field envelope. We then uncover the formation and properties of optical localized gap modes of two kinds, such as the fundamental gap solitons and dipole gap modes. Furthermore, we confirm the (in)stability regions of both localized gap modes in the respective band-gap spectrum with systematic numerical simulations relying on linear-stability analysis and direct perturbed propagation. The predicted results may enrich the nonlinear horizon to the realm of coherent atomic gases and open up a new door for optical communication and information processing.

Editing the cystine knot motif of MSTN enhances muscle development of Liang Guang Small Spotted pigs.

Myostatin (MSTN) is a member of the transforming growth factor-ß (TGF-ß) family, and functions as an inhibitor of muscle growth. Disrupting the inhibitory effect of MSTN on growth can provide an effective way to increase the muscle yield of livestock and poultry. The cysteine knot motif of TGF-ß can stabilize the structure of MSTN protein and plays an important regulatory role in the biological function of MSTN. Accordingly, in this study, we used the CRISRP/Cas9 to edit the exon 3 of MSTN in the kidney cells of Liang Guang Small Spotted pig (LPKCs), in order to disrupt the cysteine knot motif of MSTN and remove the inhibitory effect of MSTN on its target genes.MSTN-edited LPKCs were obtained through fluorescence-activated cell sorting (FACS) and used as donor cells for somatic cell nuclear transfer (SCNT) to generate cloned embryos, which were then transferred to surrogate sows to finally obtain eight MSTN-edited Liang Guang Small Spotted piglets. Among them, two survived to 10 days old. Genotyping revealed that these two piglets were gene edited heterozygotes with base deletion and substitution occurred within the coding sequence of C106 and C108 at the cystine knot motif of MSTN. These changes resulted in frameshift mutations, and conversion of C106 and C108 to other amino acids. More developments of muscles were observed at the shoulders and hips of the heterozygotes of MSTN-edited Liang Guang Small Spotted pigs. H&E analysis showed that the cross-sectional area (CSA) of myofiber inMSTN-edited pigs was significantly decreased, and the number of myofiber were significantly increased. Western blot analysis showed that the disruption of C106 and C108 did not affect the expression of MSTN protein, but significantly up-regulated the expression of its target genes such as Myf5, MyoD, Myogenin and other myogenic regulatory factors. In summary, the gene-edited pig model obtained in this study did not cause complete loss of MSTN expression, and could retain other biological functions of MSTN, thereby promoting muscle growth while minimizing the potential adverse effects on complete loss of MSTN in the Liang Guang Small Spotted pigs.

Precise editing of myostatin signal peptide by CRISPR/Cas9 increases the muscle mass of Liang Guang Small Spotted pigs.

Myostatin (MSTN), a member of the transforming growth factor-ß superfamily, is a negative regulator of muscle growth and development. Disruption of the MSTN gene in various mammalian species markedly promotes muscle growth. Previous studies have mainly focused on the disruption of the MSTN peptide coding region in pigs but not on the modification of the signal peptide region. In this study, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) system was used to successfully introduce two mutations (PVD20H and GP19del) in the MSTN signal peptide region of the indigenous Chinese pig breed, Liang Guang Small Spotted pig. Both mutations in signal peptide increased the muscle mass without inhibiting the production of mature MSTN peptide in the cells. Histological analysis revealed that the enhanced muscle mass in MSTN+/PVD20H pig was mainly due to an increase in the number of muscle fibers. The expression of MSTN in the longissimus dorsi muscle of MSTN+/PVD20H and MSTNKO/PVD20H pigs was significantly downregulated, whereas that of myogenic regulatory factors, including MyoD, Myogenin, and Myf-5, was significantly upregulated when compared to those in the longissimus dorsi muscle of wild-type pigs. Meanwhile, the mutations also activated the PI3K/Akt pathway. The results of this study indicated that precise editing of the MSTN signal peptide can enhance porcine muscle development without markedly affecting the expression of mature MSTN peptide, which could exert other beneficial biological functions in the edited pigs.

Spontaneous symmetry breaking in purely nonlinear fractional systems.

Spontaneous symmetry breaking, a spontaneous course of breaking the spatial symmetry (parity) of the system, is known to exist in many branches of physics, including condensed-matter physics, high-energy physics, nonlinear optics, and Bose-Einstein condensates. In recent years, the spontaneous symmetry breaking of solitons in nonlinear wave systems is broadly studied; understanding such a phenomenon in nonlinear fractional quantum mechanics with space fractional derivatives (the purely nonlinear fractional systems whose fundamental properties are governed by a nonlinear fractional Schrödinger equation), however, remains pending. Here, we survey symmetry breaking of solitons in fractional systems (with the fractional diffraction order being formulated by the Lévy index α) of a nonlinear double-well structure and find several kinds of soliton families in the forms of symmetric and anti-symmetric soliton states as well as asymmetric states. Linear stability and dynamical properties of these soliton states are explored relying on linear-stability analysis and direct perturbed simulations, with which the existence and stability regions of all the soliton families in the respective physical parameter space are identified.

Ultrasound-Assisted Mild Heating Treatment Improves the Emulsifying Properties of 11S Globulins.

Ultrasonic technology is often used to modify proteins. Here, we investigated the effects of ultrasound alone or in combination with other heating methods on emulsifying properties and structure of glycinin (11S globulin). Structural alterations were assessed with Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), intrinsic fluorescence spectroscopy, ultraviolet (UV) absorption spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The size distribution and zeta-potential of 11S globulin were evaluated with a particle size analyzer. An SDS-PAGE analysis showed no remarkable changes in the primary structure of 11S globulin. Ultrasound treatment disrupted the 11S globulin aggregates into small particles with uniform size, narrowed their distribution and increased their surface charge density. Fluorescent spectroscopy and second-derivative UV spectroscopy revealed that ultrasound coupled with heating induced partial unfolding of 11S globulin, increasing its flexibility and hydrophobicity. FTIR further showed that the random coil and α-helix contents were higher while ß-turn and ß-sheet contents were lower in ultrasound combined with heating group compared to the control group. Consequently, the oil-water interface entirely distributed protein and reduced the surface tension. Moreover, ultrasound combined with heating at 60 °C increased the emulsifying activity index and emulsifying stability index of 11S globulins by 6.49-folds and 2.90-folds, respectively. These findings suggest that ultrasound combined with mild heating modifies the emulsification properties of 11S globulin.

Isotope 87Rb Faraday filter with a single transmission peak resonant with atomic transition at 780 nm.

We demonstrate an isotope 87Rb Faraday anomalous dispersion optical filter (FADOF) with a single transmission peak resonant with the 5S1/2, F = 2 → 5P3/2, F' = 1, 2, 3 transitions at 780 nm with an enriched 87Rb isotope at low temperature. The isotope 87Rb FADOF achieves a single peak transmission of 74.8% with a bandwidth of 0.96 GHz. Compared with most of FADOFs operated at frequencies far from absorption, the isotope 87Rb FADOF that we have achieved can provide a transmission band exactly covering atomic transitions for many practical applications.

Purely Kerr nonlinear model admitting flat-top solitons.

We elaborate one- and two-dimensional (1D and 2D) models of media with self-repulsive cubic nonlinearity, whose local strength is subject to spatial modulation that admits the existence of flat-top solitons of various types, including fundamental ones, 1D multipoles, and 2D vortices. Previously, solitons of this type were only produced by models with competing nonlinearities. The present setting may be implemented in optics and Bose-Einstein condensates. The 1D version gives rise to an exact analytical solution for stable flat-top solitons, and generic families may be predicted by means of the Thomas-Fermi approximation. Stability of the obtained flat-top solitons is analyzed by means of the linear-stability analysis and direct simulations. Fundamental solitons and 1D multipoles with k=1 and 2 nodes, as well as vortices with winding number m=1, are completely stable. For multipoles with k≥3 and vortices with m≥2, alternating stripes of stability and instability are identified in their parameter spaces.

Disruption of the ZBED6 binding site in intron 3 of IGF2 by CRISPR/Cas9 leads to enhanced muscle development in Liang Guang Small Spotted pigs.

Insulin-like growth factor 2 (IGF2) plays an important role in the development of the foetus and in post-natal growth and development. A SNP within intron 3 of porcine IGF2 disrupts a binding site for the repressor, zinc finger BED-type containing 6 (ZBED6), leading to up-regulation of IGF2 in skeletal muscle and major effects on muscle growth, heart size, and fat deposition. This favourable mutation is common in Western commercial pig populations, but is not present in most indigenous Chinese pig breeds. Here, we described the efficient disruption of the ZBED6 binding site motif in intron 3 of IGF2 by CRISPR/Cas9 in porcine embryonic fibroblasts (PEFs) from the indigenous Chinese pig breed, Liang Guang Small Spotted pig. Disruption of the binding motif led to a drastic up-regulation of IGF2 expression in PEFs and enhanced myogenic potential and cell proliferation of PEFs. IGF2-edited pigs were then generated using somatic cell nuclear transfer. Enhanced muscle development was evident in one pig with biallelic deletion of the ZBED6 binding site motif, implying that the release of ZBED6 repression has a major effect on porcine muscle development. Our study confirmed the important effect of a mutation in the ZBED6 binding site motif on IGF2 expression and myogenesis, thus providing the basis for breeding a new line of Liang Guang Small Spotted pigs with improved lean meat percentage, a trait of great commercial value to pig producers.

The mechanism research of non-Smad dependent TAK1 signaling pathway in the treatment of bone defects by recombination BMP-2-loaded hollow hydroxyapatite microspheres/chitosan composite.

AIMS: The present study aimed to evaluate whether the non-Smad dependent TAK1 signaling pathway (BMP-2-TAK1-p38-Osx signaling pathway) played an important role in bone repair mediated by hollow hydroxyapatite (HA) microspheres/chitosan (CS) composite. METHODS: Firstly, the biological activity of rhBMP-2 released from the complex was investigated. Then, differentiation test of osteoblasts including ALP activity and calcium deposition, X-ray scoring and three-point bending test were performed. Finally, the mRNAs expression of TAK1, p38, Osx and osteogenic markers was tested by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: RhBMP-2 could be loaded and released from the complex in bioactive form. Additionally, the complex provided a prolonged period of time compared with HA/CS scaffolds. Serum ALP activity was significantly decreased in the TAK1 inhibitor group and p38 inhibitor group. In the X-ray radiography, bone callus was observed in rhBMP-2-loaded hollow HA microspheres/CS composite group. In the three-point bending test, load values in p38 inhibitor group decreased. In the animal model, the mRNA expression of BSP on day 90 was significantly decreased in the p38 inhibitor group and TAK1 inhibitor group. In MC3T3-E1 cells, the mRNA expression of OSX was remarkably up-regulated in both rhBMP-2 group or rhBMP-2-loaded hollow HA microspheres/CS composite group; while the mRNA expression of OSX was significantly down-regulated in TAK1 inhibitor group and p38 inhibitor group. CONCLUSION: The BMP-2-TAK1-p38-OSX signaling pathway may play an important role in bone formation and repair mediated by rhBMP-2-loaded hollow HA microspheres/CS composite.

Interaction of E3 Ubiquitin Ligase MARCH7 with Long Noncoding RNA MALAT1 and Autophagy-Related Protein ATG7 Promotes Autophagy and Invasion in Ovarian Cancer.

BACKGROUND/AIMS: Ubiquitin E3 ligase MARCH7 plays an important role in T cell proliferation and neuronal development. But its role in ovarian cancer remains unclear. This study aimed to investigate the role of Ubiquitin E3 ligase MARCH7 in ovarian cancer. METHODS: Real-time PCR, immunohistochemistry and western blotting analysis were performed to determine the expression of MARCH7, MALAT1 and ATG7 in ovarian cancer cell lines and clinical specimens. The role of MARCH7 in maintaining ovarian cancer malignant phenotype was examined by Wound healing assay, Matrigel invasion assays and Mouse orthotopic xenograft model. Luciferase reporter assay, western blot analysis and ChIP assay were used to determine whether MARCH7 activates TGF-ß-smad2/3 pathway by interacting with TGFßR2. RESULTS: MARCH7 interacted with MALAT1 by miR-200a (microRNA-200a). MARCH7 may function as a competing endogenous RNA (ceRNA) to regulate the expression of ATG7 by competing with miR-200a. MARCH7 regulated TGF-ß-smad2/3 pathway by interacting with TGFßR2. Inhibition of TGF-ß-smad2/3 pathway downregulated MARCH7, MALAT1 and ATG7. MiR-200a regulated TGF-ß induced autophagy, invasion and metastasis of SKOV3 cells by targeting MARCH7. MARCH7 silencing inhibited autophagy invasion and metastasis of SKOV3 cells both in vitro and in vivo. In contrast, MARCH7 overexpression promoted TGF-ß induced autophagy, invasion and metastasis of A2780 cells in vitro by depending on MALAT1 and ATG7. We also found that TGF-ß-smad2/3 pathway regulated MARCH7 and ATG7 through MALAT1. CONCLUSIONS: These findings suggested that TGFßR2-Smad2/3-MALAT1/MARCH7/ATG7 feedback loop mediated autophagy, migration and invasion in ovarian cancer.

A Theoretical Review on Interfacial Thermal Transport at the Nanoscale.

With the development of energy science and electronic technology, interfacial thermal transport has become a key issue for nanoelectronics, nanocomposites, energy transmission, and conservation, etc. The application of thermal interfacial materials and other physical methods can reliably improve the contact between joined surfaces and enhance interfacial thermal transport at the macroscale. With the growing importance of thermal management in micro/nanoscale devices, controlling and tuning the interfacial thermal resistance (ITR) at the nanoscale is an urgent task. This Review examines nanoscale interfacial thermal transport mainly from a theoretical perspective. Traditional theoretical models, multiscale models, and atomistic methodologies for predicting ITR are introduced. Based on the analysis and summary of the factors that influence ITR, new methods to control and reduce ITR at the nanoscale are described in detail. Furthermore, the challenges facing interfacial thermal management and the further progress required in this field are discussed.

Suppression of the critical collapse for one-dimensional solitons by saturable quintic nonlinear lattices.

The stabilization of one-dimensional solitons by a nonlinear lattice against the critical collapse in the focusing quintic medium is a challenging issue. We demonstrate that this purpose can be achieved by combining a nonlinear lattice and saturation of the quintic nonlinearity. The system supports three species of solitons, namely, fundamental (even-parity) ones and dipole (odd-parity) modes of on- and off-site-centered types. Very narrow fundamental solitons are found in an approximate analytical form, and systematic results for very broad unstable and moderately broad partly stable solitons, including their existence and stability areas, are produced by means of numerical methods. Stability regions of the solitons are identified by means of systematic simulations. The stability of all the soliton species obeys the Vakhitov-Kolokolov criterion.

Effects of substrates on the nonlinear optical responses of two-dimensional materials.

We investigated numerically and experimentally the achievement of strongly localized electric field and significantly enhanced second harmonic generation (SHG) in two-dimensional (2D) materials by using dielectric-metal hybrid substrates. Based on the theory of thin film interference, it was revealed that the strongest localization of electric field in a 2D material, which corresponds to the largest absorption in the metal film, could be achieved by minimizing the reflection of the combined structure (i.e., 2D material + hybrid substrate) because the transmission through the combined structure was negligible. By using MoS2 as an example, it was demonstrated that a SHG enhancement factor of ~6 could be achieved in the 17-nm-thick MoS2 layer on an Au/SiO2 substrate as compared with the single-layer MoS2 on the commonly used SiO2/Si substrates with highly efficient SHG. By employing a SiO2-SnO2/Ag/SiO2 substrate in which a 20-nm-thick dielectric film of SiO2-SnO2 was inserted in between the MoS2 layer and the Ag film, a SHG enhancement factor as large as ~18 could be realized in the 9-nm-thick MoS2 layer. Numerical simulations based on the finite-difference time-domain technique were employed to derive the enhancement factors for SHG and it was revealed that for thick MoS2 layers the SHG intensity is dominated mainly by the localization of electric field induced by the dielectric-metal hybrid substrates. The dependence of the SHG enhancement factor on the thickness of the MoS2 layer was found to be modified when the dielectric-metal hybrid substrates were adopted.

Three-photon-induced blue emission with narrow bandwidth from hot flower-like ZnO nanorods.

ZnO nanorods (NRs) self-organized into flowers were synthesized at different temperatures ranging from 100°C to 180°C by using the hydrothermal method. The existence of Zn interstitials (Zn(i)) was confirmed by X-ray photoelectron spectroscopy and a larger amount of Zn(i) was found in the ZnO NRs prepared at higher temperatures. A redshift of the emission peak of more than 15 nm was observed for the ZnO NRs under single photon excitation. The nonlinear optical properties of the flower-like ZnO NRs were characterized by using focused femtosecond laser light and strong three-photon-induced luminescence was observed at an excitation wavelength of ~750 nm. More interestingly, a large redshift of the emission peak was observed with increasing excitation intensity, resulting in efficient blue emission with a narrow bandwidth of ~30 nm. It was confirmed that the large redshift originates from the heating of the ZnO NRs to a temperature of more than 800°C and the closely packed ZnO NRs in the flowers play a crucial role in heat accumulation. The stable and efficient three-photon-induced blue emission from such ZnO NRs may find potential applications in the fields of optical display, high-temperature sensors and light therapy of tumors.

Hollow hydroxyapatite microspheres/chitosan composite as a sustained delivery vehicle for rhBMP-2 in the treatment of bone defects.

Composite scaffold comprised of hollow hydroxyapatite (HA) and chitosan (designated hHA/CS) was prepared as a delivery vehicle for recombinating human bone morphogenetic protein-2 (rhBMP-2). The in vitro and in vivo biological activities of rhBMP2 released from the composite scaffold were then investigated. The rhBMP-2 was firstly loaded into the hollow HA microspheres, and then the rhBMP2-loaded HA microspheres were further incorporated into the chitosan matrix. The chitosan not only served to bind the HA microspheres together and kept them at the implant site, but also effectively modified the release behavior of rhBMP-2. The in vitro release and bioactivity analysis confirmed that the rhBMP2 could be loaded and released from the composite scaffolds in bioactive form. In addition, the composite scaffolds significantly reduced the initial burst release of rhBMP2, and thus providing prolonged period of time (as long as 60 days) compared with CS scaffolds. In vivo bone regenerative potential of the rhBMP2-loaded composite scaffolds was evaluated in a rabbit radius defect model. The results revealed that the rate of new bone formation in the rhBMP2-loaded hHA/CS group was higher than that in both negative control and rhBMP2-loaded CS group. These observations suggest that the hHA/CS composite scaffold would be effective and feasible as a delivery vehicle for growth factors in bone regeneration and repair.