Deep Penetrating and Sensitive Targeted Magnetic Particle Imaging and Photothermal Therapy of Early-Stage Glioblastoma Based on a Biomimetic Nanoplatform.

Early diagnosis can effectively improve the survival of glioblastoma multiforme (GBM). A specific imaging technique that is simultaneously deep penetrating and sensitive to small tissue changes is desired to identify GBM. Due to its excellent features in signal contrast, detection sensitivity, and none or little attenuation in tissue, magnetic particle imaging (MPI) possesses great potential in cancer diagnosis, especially when the imaging modality is equipped with specifically targeted nanoprobes. However, when gliomas are small, the blood-brain barrier (BBB) is complete and prevents nanoprobes from entering the brain, which negates the theranostic effect. This study proposes a biomimetic nanoplatform that assist the MPI tracers in breaking through the BBB and then demonstrate a targeted and sensitive diagnosis of GBM. Afterward, the photothermal therapy and immune regulation show an excellent therapeutic effect on the GBM. It is experimentally confirmed that the MPI signal does not decay with tissue depth and shows excellent sensitivity for thousands-cells. Only small animals are conducted in this study due to the limitations of the current commercial MPI scanner, however, this research theoretically enables large animal and human studies, which encourages a promising pathway toward the noninvasive diagnosis of early-stage GBM in clinics.

Long-distance pattern projection through an unfixed multimode fiber with natural evolution strategy-based wavefront shaping.

Focusing light into an arbitrary pattern through complex media is desired in energy delivery-related scenarios and has been demonstrated feasible with the assistance of wavefront shaping. However, it still encounters challenges in terms of pattern fidelity and focusing contrast, especially in a noisy and perturbed environment. In this work, we show that the strategy relying on natural gradient ascent-based parameter optimization can help to resist noise and disturbance, enabling rapid wavefront optimization towards high-quality pattern projection through complex media. It is revealed that faster convergence and better robustness can be achieved compared with existing phase control algorithms. Meanwhile, a new fitness function based on cosine similarity is adopted for the algorithm, leading to higher focusing contrast without sacrificing similarity to the target pattern. As a result, long-distance projection of an arbitrary pattern can be accomplished with considerably enhanced performance through a 15-meter multimode fiber that is not fixed and susceptible to perturbation. With further engineering, the approach may find special interests for many biomedical applications, such as deep-tissue photon therapy and optogenetics, where free-space localized optical delivery encounters challenges.

Wavefront shaping: A versatile tool to conquer multiple scattering in multidisciplinary fields.

Optical techniques offer a wide variety of applications as light-matter interactions provide extremely sensitive mechanisms to probe or treat target media. Most of these implementations rely on the usage of ballistic or quasi-ballistic photons to achieve high spatial resolution. However, the inherent scattering nature of light in biological tissues or tissue-like scattering media constitutes a critical obstacle that has restricted the penetration depth of non-scattered photons and hence limited the implementation of most optical techniques for wider applications. In addition, the components of an optical system are usually designed and manufactured for a fixed function or performance. Recent advances in wavefront shaping have demonstrated that scattering- or component-induced phase distortions can be compensated by optimizing the wavefront of the input light pattern through iteration or by conjugating the transmission matrix of the scattering medium. This offers unprecedented opportunities in many applications to achieve controllable optical delivery or detection at depths or dynamically configurable functionalities by using scattering media to substitute conventional optical components. In this article, the recent progress of wavefront shaping in multidisciplinary fields is reviewed, from optical focusing and imaging with scattering media, functionalized devices, modulation of mode coupling, and nonlinearity in multimode fiber to multimode fiber-based applications. Apart from insights into the underlying principles and recent advances in wavefront shaping implementations, practical limitations and roadmap for future development are discussed in depth. Looking back and looking forward, it is believed that wavefront shaping holds a bright future that will open new avenues for noninvasive or minimally invasive optical interactions and arbitrary control inside deep tissues. The high degree of freedom with multiple scattering will also provide unprecedented opportunities to develop novel optical devices based on a single scattering medium (generic or customized) that can outperform traditional optical components.

Speckle-Based Optical Cryptosystem and its Application for Human Face Recognition via Deep Learning.

Face recognition has become ubiquitous for authentication or security purposes. Meanwhile, there are increasing concerns about the privacy of face images, which are sensitive biometric data and should be protected. Software-based cryptosystems are widely adopted to encrypt face images, but the security level is limited by insufficient digital secret key length or computing power. Hardware-based optical cryptosystems can generate enormously longer secret keys and enable encryption at light speed, but most reported optical methods, such as double random phase encryption, are less compatible with other systems due to system complexity. In this study, a plain yet highly efficient speckle-based optical cryptosystem is proposed and implemented. A scattering ground glass is exploited to generate physical secret keys of 17.2 gigabit length and encrypt face images via seemingly random optical speckles at light speed. Face images can then be decrypted from random speckles by a well-trained decryption neural network, such that face recognition can be realized with up to 98% accuracy. Furthermore, attack analyses are carried out to show the cryptosystem's security. Due to its high security, fast speed, and low cost, the speckle-based optical cryptosystem is suitable for practical applications and can inspire other high-security cryptosystems.

Parameter-free optimization algorithm for iterative wavefront shaping.

Optical focusing through scattering media has a significant impact on optical applications in biological tissues. Recently, iterative wavefront shaping (WFS) has been successfully used to focus light through or inside scattering media, and various heuristic algorithms have been introduced to improve the performance. While these results are encouraging, more efforts are needed to tune parameters towards robust and optimum optimization. Moreover, optimal parameters might differ for different scattering samples and experimental conditions. In this Letter, we propose a "smart" parameter-free algorithm by combining a traditional genetic algorithm with a bat algorithm, and the mutation rate can be automatically calculated through real-time feedback. Using this method in iterative WFS, one can achieve robust and optimum performance without a parameter tuning process.

Dynamic mutation enhanced particle swarm optimization for optical wavefront shaping.

Particle swarm optimization (PSO) is a well-known iterative algorithm commonly adopted in wavefront shaping for focusing light through or inside scattering media. The performance is, however, limited by premature convergence in an unstable environment. Therefore, we aim to solve this problem and enhance the focusing performance by adding a dynamic mutation operation into the plain PSO. With dynamic mutation, the "particles," or the optimized masks, are mutated with quantifiable discrepancy between the current and theoretical optimal solution, i.e., the "error rate." Gauged by that, the diversity of the "particles" is effectively expanded, and the adaptability of the algorithm to noise and instability is significantly promoted, yielding optimization approaching the theoretical optimum. The simulation and experimental results show that PSO with dynamic mutation demonstrates considerably better performance than PSO without mutation or with a constant mutation, especially under a noisy environment.

Multifunctional layered black phosphorene-based nanoplatform for disease diagnosis and treatment: a review.

As an outstanding two-dimensional material, black phosphorene, has attracted significant attention in the biomedicine field due to its large surface area, strong optical absorption, distinct bioactivity, excellent biocompatibility, and high biodegradability. In this review, the preparation and properties of black phosphorene are summarized first. Thereafter, black phosphorene-based multifunctional platforms employed for the diagnosis and treatment of diseases, including cancer, bone injuries, brain diseases, progressive oxidative diseases, and kidney injury, are reviewed in detail. This review provides a better understanding of the exciting properties of black phosphorene, such as its high drug-loading efficiency, photothermal conversion capability, high 1O2 generation efficiency, and high electrical conductivity, as well as how these properties can be exploited in biomedicine. Finally, the research perspectives of black phosphorene are discussed.