Electrospinning of a sandwich-structured membrane with sustained release capability and long-term anti-inflammatory effects for dental pulp regeneration

Current electro spun membranes used for pulp capping still lack the sustained-release capability and long-term anti-inflammatory effects that are favorable for dental pulp regeneration.In this work,a single-layered poly(lac tic acid)(PLA)electro spun membrane loaded with amorphous calcium phosphate(ACP)and aspirin(PLA/ACP/Aspirin membrane,i.e.,PA A membrane)is sandwiched between two poly(lactic-co-glycolic acid)(PLGA)electro spun membranes as a novel sandwich-structured PLGA and PA A composite electro spun membrane(PLGA-PAA membrane)to resolve the need for sustained-release design and anti-inflammatory effects.Contact angle measurements indicate that the PLGA-PAA membrane is more hydrophilic than the PAA membrane.An in vitro release study reveals that PLGA membranes coated on PAA membrane could slightly slow down ion release,while signiificantly prolonging aspirin release.We also co-cultured membranes with dental pulp stem cells(DPSCs)and human monocytic THP-1 cells to evaluate their osteogenic ability and anti-inflammatory effects,respectively.Compared with the PAA membrane,the PLGA-PAA membrane promotes cell adhesion,proliferation,and osteogenic differentiation.A prolonged anti-inflammatory effect of up to 18 days is also observed in the PLGA-PAA group.The results suggest a promising strategy for fabricating an electro spun membrane system with controlled release capabilities and long-term anti-inflammatory effects for use as pulp-capping material for regeneration of the dentin-pulp complex.

Two-dimensional materials in photonic integrated circuits:recent developments and future perspectives[Invited]

The heterogeneous integration of photonic integrated circuits(PICs)with a diverse range of optoelectronic materials has emerged as a transformative approach,propelling photonic chips toward larger scales,superior performance,and advanced integration levels.Notably,two-dimensional(2D)materials,such as graphene,transition metal dichalcogenides(TMDCs),black phosphorus(BP),and hexagonal boron nitride(hBN),exhibit remarkable device performance and integration capabilities,offering promising potential for large-scale implementation in PICs.In this paper,we first present a comprehensive review of recent progress,systematically categorizing the integration of photonic circuits with 2D materials based on their types while also emphasizing their unique advantages.Then,we discuss the integration approaches of 2D materials with PICs.We also summarize the technical challenges in the heterogeneous integration of 2D materials in photonics and envision their immense potential for future applications in PICs.

Co‑packaged optics(CPO):status,challenges,and solutions

Due to the rise of 5G,IoT,AI,and high-performance computing applications,datacenter trafc has grown at a compound annual growth rate of nearly 30%.Furthermore,nearly three-fourths of the datacenter trafc resides within datacenters.The conventional pluggable optics increases at a much slower rate than that of datacenter trafc.The gap between application requirements and the capability of conventional pluggable optics keeps increasing,a trend that is unsustainable.Copackaged optics(CPO)is a disruptive approach to increasing the interconnecting bandwidth density and energy efciency by dramatically shortening the electrical link length through advanced packaging and co-optimization of electronics and photonics.CPO is widely regarded as a promising solution for future datacenter interconnections,and silicon platform is the most promising platform for large-scale integration.Leading international companies(e.g.,Intel,Broadcom and IBM)have heavily investigated in CPO technology,an inter-disciplinary research feld that involves photonic devices,integrated circuits design,packaging,photonic device modeling,electronic-photonic co-simulation,applications,and standardization.This review aims to provide the readers a comprehensive overview of the state-of-the-art progress of CPO in silicon platform,identify the key challenges,and point out the potential solutions,hoping to encourage collaboration between diferent research felds to accelerate the development of CPO technology.

16-channel photonic–electric co-designed silicon transmitter with ultra-low power consumption

A hybrid integrated 16-channel silicon transmitter based on co-designed photonic integrated circuits(PICs) and electrical chiplets is demonstrated. The driver in the 65 nm CMOS process employs the combination of a distributed architecture, two-tap feedforward equalization(FFE), and a push–pull output stage, exhibiting an estimated differential output swing of 4.0V_(pp). The rms jitter of 2.0 ps is achieved at 50 Gb/s under nonreturnto-zero on–off keying(NRZ-OOK) modulation. The PICs are fabricated on a standard silicon-on-insulator platform and consist of 16 parallel silicon dual-drive Mach–Zehnder modulators on a single chip. The chip-on-board co-packaged Si transmitter is constituted by the multichannel chiplets without any off-chip bias control, which significantly simplifies the system complexity. Experimentally, the open and clear optical eye diagrams of selected channels up to 50 Gb/s OOK with extinction ratios exceeding 3 dB are obtained without any digital signal processing. The power consumption of the Si transmitter with a high integration density featuring a throughput up to 800 Gb/s is only 5.35 p J/bit, indicating a great potential for massively parallel terabit-scale optical interconnects for future hyperscale data centers and high-performance computing systems.

Demonstration of an on-chip TE-pass polarizer using a silicon hybrid plasmonic grating

An on-chip, high extinction ratio transverse electric(TE)-pass polarizer using a silicon hybrid plasmonic grating is proposed and experimentally demonstrated. Utilizing plasmonics to manipulate the effective index and mode distribution, the transverse magnetic mode is reflected and absorbed, while the TE mode passes through with relatively low propagation loss. For a 6-μm-long device, the measurement result shows that the extinction ratio in the wavelength range of 1.52 to 1.58 μm varies from 24 to 33.7 dB and the insertion loss is 2.8–4.9 dB. Moreover,the structure exhibits large alignment tolerance and is compatible with silicon-on-insulator fabrication technology.

Single-drive high-speed lumped depletion-type modulators toward 10 fJ/bit energy consumption

Reduction of modulator energy consumption to 10 fJ∕bit is essential for the sustainable development of communication systems.Lumped modulators might be a viable solution if instructed by a complete theory system.Here,we present a complete analytical electro-optic response theory,energy consumption analysis,and eye diagrams on absolute scales for lumped modulators.Consequently the speed limitation is understood and alleviated by single-drive configuration,and comprehensive knowledge into the energy dependence on structural parameters significantly reduces energy consumption.The results show that silicon modulation energy as low as 80.8 and 21.5 fJ∕bit can be achieved at 28 Gbd under 50 and 10 Ω impedance drivers,respectively.A 50 Gbd modulation is also shown to be possible.The analytical models can be extended to lumped modulators on other material platforms and offer a promising solution to the current challenges of modulation energy reduction.

In vitro immunomodulation of magnesium on monocytic cell toward anti-inflammatory macrophages

Biodegradable magnesium(Mg)has shown great potential advantages over current bone fixation devices and vascular scaffold technologies;however,there are few reports on the immunomodulation of corrosive Mg products,the micron-sized Mg particles(MgMPs).Human monocytic leukemia cell line THP-1 was set as the in vitro cell model to estimate the immunomodulation of MgMPs on cell proliferation,apoptosis,polarization and inflammatory reaction.Our results indicated highconcentration of Mg^2+ demoted the proliferation of the THP-1 cells and,especially,THP-1-derived macrophages,which was a potential factor that could affect cell function,but meanwhile,cell apoptosis was almost not affected by Mg^2+.In particular,the inflammation regulatory effects of MgMPs were investigated.Macrophages exposed to Mg^2+ exhibited down-regulated expressions of M1 subtype markers and secretions of pro-inflammatory cytokines,up-regulated expression of M2 subtype marker and secretion of anti-inflammatory cytokine.These results indicated Mg^2+ could convert macrophages from M0 to M2 phenotype,and the bioeffects of MgMPs on human inflammatory cells were most likely due to the Mg^2+-induced NF-jB activation reduction.Together,our results proved Mg^2+ could be used as a new anti-inflammatory agent to suppress inflammation in clinical applications,which may provide new ideas for studying the immunomodulation of Mg-based implants on human immune system.

Hybrid-integrated high-performance microwave photonic filter with switchable response

The integrated microwave photonic filter(MPF),as a compelling candidate for next-generation radio-frequency(RF)applications,has been widely investigated for decades.However,most integrated MPFs reported thus far have merely incorporated passive photonic components onto a chip-scale platform,while all necessary active devices are still bulk and discrete.Though few attempts to higher photonic integration of MPFs have been executed,the achieved filtering performances are fairly limited,which impedes the pathway to practical deployments.Here,we demonstrate,for the first time to our knowledge,an all-integrated MPF combined with high filtering performances,through hybrid integration of an In P chip-based laser and a monolithic silicon photonic circuit consisting of a dual-drive Mach–Zehnder modulator,a high-Q ring resonator,and a photodetector.This integrated MPF exhibits a high spectral resolution as narrow as 360 MHz,a wide-frequency tunable range covering the S-band to K-band(3 to 25 GHz),and a large rejection ratio of>40 d B.Moreover,the filtering response can be agilely switched between the bandpass and band-stop function with a transient respond time(48μs).Compared with previous MPFs in a similar integration level,the obtained spectral resolution in this work is dramatically improved by nearly one order of magnitude,while the valid frequency tunable range is broadened more than twice,which can satisfy the essential filtering requirements in actual RF systems.As a paradigm demonstration oriented to real-world scenarios,high-resolution RF filtering of realistic microwave signals aiming for interference rejection and channel selection is performed.Our work points out a feasible route to a miniaturized,high-performance,and cost-effective MPF leveraging hybrid integration approach,thus enabling a range of RF applications from wireless communication to radar toward the higher-frequency region,more compact size,and lower power consumption.

A controllable coupling structure for silicon microring resonators based on adiabatic elimination

Optical microring resonators are extensively employed in a wide range of physical studies and applications due to the resonance enhancement property.Incorporating coupling control of a microring resonator is necessary in many scenarios,but modifications are essentially added to the resonator and impair the capability of optical enhancement.Here,we propose a flexible coupling structure based on adiabatic elimination that allows low-loss active coupling control without any modifications to the resonators.The self-coupling coefficient can be monotonically or non-monotonically controllable by the proposed coupler,potentially at a high speed.The characteristic of the coupler when implemented in silicon microring resonators is investigated in detail using substantiated analytical theory and experiments.This work provides a general method in coupling control while ensuring the resonance enhancement property,making active coupling control in a resonator-waveguide system feasible.