Biomimetic Ghost Nanomedicine-Based Optotheranostics for Cancer.

Theranostic medicine combines diagnostics and therapeutics, focusing on solid tumors at minimal doses. Optically activated photosensitizers are significant examples owing to their photophysical and chemical properties. Several optotheranostics have been tested that convert light to imaging signals, therapeutic radicals, and heat. Upon light exposure, conjugated photosensitizers kill tumor cells by producing reactive oxygen species and heat or by releasing cancer antigens. Despite clinical trials, these molecularly conjugated photosensitizers require protection from their surroundings and a localized direction for site-specific delivery during blood circulation. Therefore, cell membrane biomimetic ghosts have been proposed for precise and safe delivery of these optically active large molecules, which are clinically relevant because of their biocompatibility, long circulation time, bypass of immune cell recognition, and targeting ability. This review focuses on the role of biomimetic nanoparticles in the treatment and diagnosis of tumors through light-mediated diagnostics and therapy, providing insights into their preclinical and clinical status.

A Fluorinated BODIPY-Based Zirconium Metal-Organic Framework for In Vivo Enhanced Photodynamic Therapy.

Photodynamic therapy (PDT), an emergent noninvasive cancer treatment, is largely dependent on the presence of efficient photosensitizers (PSs) and a sufficient oxygen supply. However, the therapeutic efficacy of PSs is greatly compromised by poor solubility, aggregation tendency, and oxygen depletion within solid tumors during PDT in hypoxic microenvironments. Despite the potential of PS-based metal-organic frameworks (MOFs), addressing hypoxia remains challenging. Boron dipyrromethene (BODIPY) chromophores, with excellent photostability, have exhibited great potential in PDT and bioimaging. However, their practical application suffers from limited chemical stability under harsh MOF synthesis conditions. Herein, we report the synthesis of the first example of a Zr-based MOF, namely, 69-L2, exclusively constructed from the BODIPY-derived ligands via a single-crystal to single-crystal post-synthetic exchange, where a direct solvothermal method is not applicable. To increase the PDT performance in hypoxia, we modify 69-L2 with fluorinated phosphate-functionalized methoxy poly(ethylene glycol). The resulting 69-L2@F is an oxygen carrier, enabling tumor oxygenation and simultaneously acting as a PS for reactive oxygen species (ROS) generation under LED irradiation. We demonstrate that 69-L2@F has an enhanced PDT effect in triple-negative breast cancer MDA-MB-231 cells under both normoxia and hypoxia. Following positive results, we evaluated the in vivo activity of 69-L2@F with a hydrogel, enabling local therapy in a triple-negative breast cancer mice model and achieving exceptional antitumor efficacy in only 2 days. We envision BODIPY-based Zr-MOFs to provide a solution for hypoxia relief and maximize efficacy during in vivo PDT, offering new insights into the design of promising MOF-based PSs for hypoxic tumors.

Hydrogels for RNA delivery.

RNA-based therapeutics have shown tremendous promise in disease intervention at the genetic level, and some have been approved for clinical use, including the recent COVID-19 messenger RNA vaccines. The clinical success of RNA therapy is largely dependent on the use of chemical modification, ligand conjugation or non-viral nanoparticles to improve RNA stability and facilitate intracellular delivery. Unlike molecular-level or nanoscale approaches, macroscopic hydrogels are soft, water-swollen three-dimensional structures that possess remarkable features such as biodegradability, tunable physiochemical properties and injectability, and recently they have attracted enormous attention for use in RNA therapy. Specifically, hydrogels can be engineered to exert precise spatiotemporal control over the release of RNA therapeutics, potentially minimizing systemic toxicity and enhancing in vivo efficacy. This Review provides a comprehensive overview of hydrogel loading of RNAs and hydrogel design for controlled release, highlights their biomedical applications and offers our perspectives on the opportunities and challenges in this exciting field of RNA delivery.

'Passive' nanoparticles for organ-selective systemic delivery: design, mechanism and perspective.

Nanotechnology has shown tremendous success in the drug delivery field for more effective and safer therapy, and has recently enabled the clinical approval of RNA medicine, a new class of therapeutics. Various nanoparticle strategies have been developed to improve the systemic delivery of therapeutics, among which surface modification of targeting ligands on nanoparticles has been widely explored for 'active' delivery to a specific organ or diseased tissue. Meanwhile, compelling evidence has recently been reported that organ-selective targeting may also be achievable by systemic administration of nanoparticles without surface ligand modification. In this Review, we highlight this unique set of 'passive' nanoparticles and their compositions and mechanisms for organ-selective delivery. In particular, the lipid-based, polymer-based, and biomimetic nanoparticles with tropism to different specific organs after intravenous administration are summarized. The underlying mechanisms (e.g., protein corona and size effect) of these nanosystems for organ selectivity are also extensively discussed. We further provide perspectives on the opportunities and challenges in this exciting area of organ-selective systemic nanoparticle delivery.

Infanticide vs. inherited cardiac arrhythmias.

AIMS: In 2003, an Australian woman was convicted by a jury of smothering and killing her four children over a 10-year period. Each child died suddenly and unexpectedly during a sleep period, at ages ranging from 19 days to 18 months. In 2019 we were asked to investigate if a genetic cause could explain the children's deaths as part of an inquiry into the mother's convictions. METHODS AND RESULTS: Whole genomes or exomes of the mother and her four children were sequenced. Functional analysis of a novel CALM2 variant was performed by measuring Ca2+-binding affinity, interaction with calcium channels and channel function. We found two children had a novel calmodulin variant (CALM2 G114R) that was inherited maternally. Three genes (CALM1-3) encode identical calmodulin proteins. A variant in the corresponding residue of CALM3 (G114W) was recently reported in a child who died suddenly at age 4 and a sibling who suffered a cardiac arrest at age 5. We show that CALM2 G114R impairs calmodulin's ability to bind calcium and regulate two pivotal calcium channels (CaV1.2 and RyR2) involved in cardiac excitation contraction coupling. The deleterious effects of G114R are similar to those produced by G114W and N98S, which are considered arrhythmogenic and cause sudden cardiac death in children. CONCLUSION: A novel functional calmodulin variant (G114R) predicted to cause idiopathic ventricular fibrillation, catecholaminergic polymorphic ventricular tachycardia, or mild long QT syndrome was present in two children. A fatal arrhythmic event may have been triggered by their intercurrent infections. Thus, calmodulinopathy emerges as a reasonable explanation for a natural cause of their deaths.

Intrinsically Bioactive Cryogels Based on Platelet Lysate Nanocomposites for Hemostasis Applications.

The currently used hemostatic agents are highly effective in stopping hemorrhages but have a limited role in the modulation of the wound-healing environment. Herein, we propose an intrinsically bioactive hemostatic cryogel based on platelet lysate (PL) and aldehyde-functionalized cellulose nanocrystals (a-CNCs). PL has attracted great attention as an inexpensive milieu of therapeutically relevant proteins; however, its application as a hemostatic agent exhibits serious constraints (e.g., structural integrity and short shelf-life). The incorporation of a-CNCs reinforced the low-strength PL matrix by covalent cross-linking its amine groups that exhibit an elastic interconnected porous network after full cryogelation. Upon blood immersion, the PL-CNC cryogels absorbed higher volumes of blood at a faster rate than commercial hemostatic porcine gelatin sponges. Simultaneously, the cryogels released biomolecules that increased stem cell proliferation, metabolic activity, and migration as well as downregulated the expression of markers of the fibrinolytic process. In an in vivo liver defect model, PL-CNC cryogels showed similar hemostatic performance in comparison with gelatin sponges and normal material-induced tissue response upon subcutaneous implantation. Overall, owing to their structure and bioactive composition, the proposed PL-CNC cryogels provide an alternative off-the-shelf hemostatic and antibacterial biomaterial with the potential to deliver therapeutically relevant proteins in situ.

Multifunctional magnetic-responsive hydrogels to engineer tendon-to-bone interface.

Photocrosslinkable magnetic hydrogels are attracting great interest for tissue engineering strategies due to their versatility and multifunctionality, including their remote controllability ex vivo, thus enabling engineering complex tissue interfaces. This study reports the development of a photocrosslinkable magnetic responsive hydrogel made of methacrylated chondroitin sulfate (MA-CS) enriched with platelet lysate (PL) with tunable features, envisioning their application in tendon-to-bone interface. MA-CS coated iron-based magnetic nanoparticles were incorporated to provide magnetic responsiveness to the hydrogel. Osteogenically differentiated adipose-derived stem cells and/or tendon-derived cells were encapsulated within the hydrogel, proliferating and expressing bone- and tendon-related markers. External magnetic field (EMF) application modulated the swelling, degradation and release of PL-derived growth factors, and impacted both cell morphology and the expression and synthesis of tendon- and bone-like matrix with a more evident effect in co-cultures. Overall, the developed magnetic responsive hydrogel represents a potential cell carrier system for interfacial tissue engineering with EMF-controlled properties.

Biomimetic bright optotheranostics for metastasis monitoring and multimodal image-guided breast cancer therapeutics.

Nanoparticle formulations blending optical imaging contrast agents and therapeutics have been a cornerstone of preclinical theranostic applications. However, nanoparticle-based theranostics clinical translation faces challenges on reproducibility, brightness, photostability, biocompatibility, and selective tumor targeting and penetration. In this study, we integrate multimodal imaging and therapeutics within cancer cell-derived nanovesicles, leading to biomimetic bright optotheranostics for monitoring cancer metastasis. Upon NIR light irradiation, the engineered optotheranostics enables deep visualization and precise localization of metastatic lung, liver, and solid breast tumors along with solid tumor ablation. Metastatic cell-derived nanovesicles (∼80 ± 5 nm) are engineered to encapsulate imaging (emissive organic dye and gold nanoparticles) and therapeutic agents (anticancer drug doxorubicin and photothermally active organic indocyanine green dye). Systemic administration of biomimetic bright optotheranostic nanoparticles shows escape from mononuclear phagocytic clearance with (i) rapid tumor accumulation (3 h) and retention (up to 168 h), (ii) real-time monitoring of metastatic lung, liver, and solid breast tumors and (iii) 3-fold image-guided solid tumor reduction. These findings are supported by an improvement of X-ray, fluorescence, and photoacoustic signals while demonstrating a tumor reduction (201 mm3) in comparison with single therapies that includes chemotherapy (134 mm3), photodynamic therapy (72 mm3), and photothermal therapy (88mm3). The proposed innovative platform opens new avenues to improve cancer diagnosis and treatment outcomes by allowing the monitorization of cancer metastasis, allowing the precise cancer imaging, and delivering synergistic therapeutic agents at the solid tumor site.

A large-scale machine learning analysis of inorganic nanoparticles in preclinical cancer research.

Owing to their distinct physical and chemical properties, inorganic nanoparticles (NPs) have shown promising results in preclinical cancer therapy, but designing and engineering them for effective therapeutic purposes remains a challenge. Although a comprehensive database of inorganic NP research is not currently available, it is crucial for developing effective cancer therapies. In this context, machine learning (ML) has emerged as a transformative tool, but its adaptation to nanomedicine is hindered by inexistent or small datasets. Here we assembled a large database of inorganic NPs, comprising experimental datasets from 745 preclinical studies in cancer nanomedicine. Using descriptive statistics and explainable ML models we mined this database to gain knowledge of inorganic NP design patterns and inform future NP research for cancer treatment. Our analyses suggest that NP shape and therapy type are prominent features in determining in vivo efficacy, measured as a percentage of tumour reduction. Moreover, our database provides a large-scale open-access resource for discriminative ML that the broader nanotechnology community can utilize. Our work blueprints data mining for translational cancer research and offers evidence for standardizing NP reporting to accelerate and de-risk inorganic NP-based drug delivery, which may help to improve patient outcomes in clinical settings.

Bioinspired and biomimetic cancer-cell-derived membrane nanovesicles for preclinical tumor-targeted nanotheranostics.

Bioinspired cell-membrane-camouflaged nanohybrids have been proposed to enhance tumor targeting by harnessing their immune escape and self-recognition abilities. In this study, we introduce cancer-cell-derived membrane nanovesicles (CCMVs) integrated with gold nanorods (AuVNRs) in addition to therapeutic and imaging cargos such as doxorubicin and indocyanine green. This approach enhances targeted tumor imaging and enables synergistic chemo-phototherapeutics for solid tumors. CCMVs demonstrate significant tumor penetration and retention, serving as nanotheranostics with accessible surface biomarkers, biomimicking properties, and homologous targeting abilities. By evading uptake by the mononuclear phagocytic system, CCMVs can diffuse into the deep tumor core, leading to precise tumor reduction while preserving the surrounding healthy tissues. Notably, intravenous administration of these theranostic agents ensures biocompatibility, as evidenced by a survival period of approximately two months (up to 63 days) without any observed side effects. Our findings underscore the diagnostic and therapeutic potential of this biomimetic nanotheranostics platform.

Scorpion envenomation in Brazil: Current scenario and perspectives for containing an increasing health problem.

Opportunistic scorpion species can colonize urban environments, establishing high-density communities that enhance the chances of human accidents. This scenario has been taking place in Brazil, in which some Tityus species have taken city centers, causing an explosion in the number of scorpion envenoming cases. The characteristics of this scorpionism epidemic in Brazil is discussed in the present work. The number of Brazilian scorpion stings has surpassed 120,000 cases in 2017, and has been maintained above this number ever since, representing a more than 3-fold increase in 10 years, which was higher than the number of cases for most of the neglected tropical diseases in the country. The escalation in scorpionism cases is even higher in some regions of Brazil. Fortunately, the proportion of mild cases has also increased in the analyzed period, as well as the number of victims seeking for medical attention within the first hour after the accident. The species Tityus serrulatus, Tityus stigmurus, Tityus bahiensis, and Tityus obscurus are traditionally accountable for most of the scorpion accidents in different regions of Brazil, but other species deserve to be closely watched. Despite scorpionism being a notable health problem in Brazil, accident prevention and pest control regarding this venomous animal have not been properly addressed by the scientific community nor by policy makers. Therefore, this review also aims to point possible fields of research that could help to contain the aggravation of the current scorpionism landscape in Brazil.

SARS-CoV-2 E and 3a Proteins Are Inducers of Pannexin Currents.

Controversial reports have suggested that SARS-CoV E and 3a proteins are plasma membrane viroporins. Here, we aimed at better characterizing the cellular responses induced by these proteins. First, we show that expression of SARS-CoV-2 E or 3a protein in CHO cells gives rise to cells with newly acquired round shapes that detach from the Petri dish. This suggests that cell death is induced upon expression of E or 3a protein. We confirmed this by using flow cytometry. In adhering cells expressing E or 3a protein, the whole-cell currents were not different from those of the control, suggesting that E and 3a proteins are not plasma membrane viroporins. In contrast, recording the currents on detached cells uncovered outwardly rectifying currents much larger than those observed in the control. We illustrate for the first time that carbenoxolone and probenecid block these outwardly rectifying currents; thus, these currents are most probably conducted by pannexin channels that are activated by cell morphology changes and also potentially by cell death. The truncation of C-terminal PDZ binding motifs reduces the proportion of dying cells but does not prevent these outwardly rectifying currents. This suggests distinct pathways for the induction of these cellular events by the two proteins. We conclude that SARS-CoV-2 E and 3a proteins are not viroporins expressed at the plasma membrane.

Nanodelivery of nucleic acids.

There is growing need for a safe, efficient, specific and non-pathogenic means for delivery of gene therapy materials. Nanomaterials for nucleic acid delivery offer an unprecedented opportunity to overcome these drawbacks; owing to their tunability with diverse physico-chemical properties, they can readily be functionalized with any type of biomolecules/moieties for selective targeting. Nucleic acid therapeutics such as antisense DNA, mRNA, small interfering RNA (siRNA) or microRNA (miRNA) have been widely explored to modulate DNA or RNA expression Strikingly, gene therapies combined with nanoscale delivery systems have broadened the therapeutic and biomedical applications of these molecules, such as bioanalysis, gene silencing, protein replacement and vaccines. Here, we overview how to design smart nucleic acid delivery methods, which provide functionality and efficacy in the layout of molecular diagnostics and therapeutic systems. It is crucial to outline some of the general design considerations of nucleic acid delivery nanoparticles, their extraordinary properties and the structure-function relationships of these nanomaterials with biological systems and diseased cells and tissues.

Nanomedicine-based strategies to target and modulate the tumor microenvironment.

The interest in nanomedicine for cancer theranostics has grown significantly over the past few decades. However, these nanomedicines need to overcome several physiological barriers intrinsic to the tumor microenvironment (TME) before reaching their target. Intrinsic tumor genetic/phenotypic variations, along with intratumor heterogeneity, provide different cues to each cancer type, making each patient with cancer unique. This brings additional challenges in translating nanotechnology-based systems into clinically reliable therapies. To develop efficient therapeutic strategies, it is important to understand the dynamic interactions between TME players and the complex mechanisms involved, because they constitute invaluable targets to dismantle tumor progression. In this review, we discuss the latest nanotechnology-based strategies for cancer diagnosis and therapy as well as the potential targets for the design of future anticancer nanomedicines.

Multifunctional Surfaces for Improving Soft Tissue Integration.

Metallic implants are widely used in diverse clinical applications to aid in recovery from lesions or to replace native hard tissues. However, the lack of integration of metallic surfaces with soft tissue interfaces causes the occurrence of biomaterial-associated infections, which can trigger a complicated inflammatory response and, ultimately, implant failure. Here, a multifunctional implant surface showing nanoscale anisotropy, based on the controlled deposition of cellulose nanocrystals (CNC), and biological activity derived from platelet lysate (PL) biomolecules sequestered and presented on CNC surface, is proposed. The anisotropic radial nanopatterns are produced on polished titanium surfaces by spin-coating CNC at high speed. Furthermore, CNC surface chemistry allows to further sequester and form a coating of bioactive molecules derived from PL. The surface anisotropy provided by CNC guides fibroblasts growth and alignment up to 14 days of culture. Moreover, PL-derived biomolecules polarize macrophages toward the M2-like anti-inflammatory phenotype. These results suggest that the developed multifunctional surfaces can promote soft tissue integration to metallic implants and, at the same time, prevent bacterial invasion, tissue inflammation, and failure of biomedical metallic implants.

Injectable hyaluronic acid and platelet lysate-derived granular hydrogels for biomedical applications.

Towards the repair of damaged tissues, numerous scaffolds have been fabricated to recreate the complex extracellular matrix (ECM) environment to support desired cell behaviors; however, it is often challenging to design scaffolds with the requisite cell-anchorage sites, mechanical stability, and tailorable physicochemical properties necessary for many applications. To address this and to improve on the properties of hyaluronic acid (HA) hydrogels, we combined photocrosslinkable norbornene-modified HA (NorHA) with human platelet lysate (PL). These PL-NorHA hybrid hydrogels supported the adhesion of cells when compared to NorHA hydrogels without PL, exhibited tailorable physicochemical properties based on the concentration of individual components, and released proteins over time. Using microfluidic techniques with on-chip mixing of NorHA and PL and subsequent photocrosslinking, spherical PL-NorHA microgels with a hierarchical fibrillar network were fabricated that exhibited the sustained delivery of PL proteins. Microgels could be jammed into granular hydrogels that exhibited shear-thinning and self-healing properties, enabling ejection from syringes and the fabrication of stable 3D constructs with 3D printing. Again, the inclusion of PL enhanced cellular interactions with the microgel structures. Overall, the combination of biomolecules and fibrin self-assembly arising from the enriched milieu of PL-derived proteins improved the bioactivity of HA-based hydrogels, enabling the formation of dynamic systems with modular design. The granular systems can be engineered to meet the complex demands of functional tissue repair using versatile processing techniques, such as with 3D printing.

Cellulose nanocrystals of variable sulfation degrees can sequester specific platelet lysate-derived biomolecules to modulate stem cell response.

The surface chemistry of cellulose nanocrystals was engineered to show variable sulfation degrees, which was exploited to modulate platelet lysate-derived biomolecule sequestration and presentation. The protein coronas developed on CNC surfaces were characterized and it was demonstrated how they promote different signaling effects on human adipose-derived stem cell behavior.

Human platelet lysate-based nanocomposite bioink for bioprinting hierarchical fibrillar structures.

Three-dimensional (3D) bioprinting holds the promise to fabricate tissue and organ substitutes for regenerative medicine. However, the lack of bioactive inks to fabricate and support functional living constructs is one of the main limitations hindering the progress of this technology. In this study, a biofunctional human-based nanocomposite bioink (HUink) composed of platelet lysate hydrogels reinforced by cellulose nanocrystals is reported. When combined with suspended bioprinting technologies, HUink allows the biofabrication of 3D freeform constructs with high resolution and integrity, mimicking the hierarchical nano-to-macro fibrillary composition of native tissues. Remarkably, HUink supports bioprinting of stem cells with high viability immediately after extrusion and over long-term cell culture without the need for additional biochemical or animal-derived media supplementation. As opposed to typical polymer-based bioinks, the pool of growth factors, cytokines and adhesion proteins in HUink boosts cell spreading and proliferation, stimulating the fast production of cell-secreted extracellular matrix. This innovative bioprinting platform with unpaired biofunctionality allows the fabrication of complex freeform cell-laden constructs that can ultimately be applied in the development of xeno-free 3D tissue models for in vitro research or to develop tissue and organ surrogates for clinical applications.

Injectable and Magnetic Responsive Hydrogels with Bioinspired Ordered Structures.

Injectable hydrogels are particularly interesting for applications in minimally invasive tissue engineering and regenerative medicine strategies. However, the typical isotropic microstructure of these biomaterials limits their potential for the regeneration of ordered tissues. In the present work, we decorated rod-shaped cellulose nanocrystals with magnetic nanoparticles and coated these with polydopamine and polyethylene glycol polymer brushes to obtain chemical and colloidal stable nanoparticles. Then, these nanoparticles (0.1-0.5 wt %) were incorporated within gelatin hydrogels, creating injectable and magnetically responsive materials with potential for various biomedical applications. Nanoparticle alignment within the hydrogel matrix was achieved under exposure to uniform low magnetic fields (108 mT), resulting in biomaterials with directional microstructure and anisotropic mechanical properties. The biological performance of these nanocomposite hydrogels was studied using adipose tissue derived human stem cells. Cells encapsulated in the nanocomposite hydrogels showed high rates of viability demonstrating that the nanocomposite biomaterials are not cytotoxic. Remarkably, the microstructural patterns stemming from nanoparticle alignment induced the directional growth of seeded and, to a lower extent, encapsulated cells in the hydrogels, suggesting that this injectable system might find application in both cellular and acellular strategies targeting the regeneration of anisotropic tissues.

Human-based fibrillar nanocomposite hydrogels as bioinstructive matrices to tune stem cell behavior.

The extracellular matrix (ECM)-biomimetic fibrillar structure of platelet lysate (PL) gels along with their enriched milieu of biomolecules has drawn significant interest in regenerative medicine applications. However, PL-based gels have poor structural stability, which severely limits their performance as a bioinstructive biomaterial. Here, rod-shaped cellulose nanocrystals (CNC) are used as a novel approach to modulate the physical and biochemical microenvironment of PL gels enabling their effective use as injectable human-based cell scaffolds with a level of biomimicry that is difficult to recreate with synthetic biomaterials. The incorporation of CNC (0 to 0.61 wt%) into the PL fibrillar network during the coagulation cascade leads to decreased fiber branching, increased interfiber porosity (from 66 to 83%) and modulates fiber (from 1.4 ± 0.7 to 27 ± 12 kPa) and bulk hydrogel (from 18 ± 4 to 1256 ± 82 Pa) mechanical properties. As a result of these physicochemical alterations, nanocomposite PL hydrogels resist the typical extensive clot retraction (from 76 ± 1 to 24 ± 3 at day 7) and show favored retention of PL bioactive molecules. The feedback of these cues on the fate of human adipose-derived stem cells is evaluated, showing how it can be explored to modulate the commitment of encapsulated stem cells toward different genetic phenotypes without the need for additional external biological stimuli. These fibrillar nanocomposite hydrogels allow therefore the exploration of the outstanding biological properties of human-based PL as an efficient engineered ECM which can be tailored to trigger specific regenerative pathways in minimal invasive strategies.