Lipid-based nanosystems: the next generation of cancer immune therapy.

Immunotherapy has become an important part of the oncotherapy arsenal. Its applicability in various cancer types is impressive, as well as its use of endogenous mechanisms to achieve desired ends. However, off-target or on-target-off-tumor toxicity, limited activity, lack of control in combination treatments and, especially for solid tumors, low local accumulation, have collectively limited clinical use thereof. These limitations are partially alleviated by delivery systems. Lipid-based nanoparticles (NPs) have emerged as revolutionary carriers due to favorable physicochemical characteristics, with specific applications and strengths particularly useful in immunotherapeutic agent delivery. The aim of this review is to highlight the challenges faced by immunotherapy and how lipid-based NPs have been, and may be further utilized to address such challenges. We discuss recent fundamental and clinical applications of NPs in a range of areas and provide a detailed discussion of the main obstacles in immune checkpoint inhibition therapies, adoptive cellular therapies, and cytokine therapies. We highlight how lipid-based nanosystems could address these through either delivery, direct modulation of the immune system, or targeting of the immunosuppressive tumor microenvironment. We explore advanced and emerging liposomal and lipid nanoparticle (LNP) systems for nucleic acid delivery, intrinsic and extrinsic stimulus-responsive formulations, and biomimetic lipid-based nanosystems in immunotherapy. Finally, we discuss the key challenges relating to the clinical use of lipid-based NP immunotherapies, suggesting future research directions for the near term to realize the potential of these innovative lipid-based nanosystems, as they become the crucial steppingstone towards the necessary enhancement of the efficacy of immunotherapy.

Increased human papillomavirus viral load is correlated to higher severity of cervical disease and poorer clinical outcome: A systematic review.

Cervical cancer is the fourth most common cancer in women worldwide and is caused by persistent infection with high-risk types of human papillomavirus (HPV). HPV viral load, the amount of HPV DNA in a sample, has been suggested to correlate with cervical disease severity, and with clinical outcome of cervical cancer. In this systematic review, we searched three databases (EMBASE, PubMed, Web of Science) to examine the current evidence on the association between HPV viral load in cervical samples and disease severity, as well as clinical outcome. After exclusion of articles not on HPV, cervical cancer, or containing clinical outcomes, 85 original studies involving 173 746 women were included. The vast majority (73/85 = 85.9%) reported that a higher viral load was correlated with higher disease severity or worse clinical outcome. Several studies reported either no correlation (3/85 = 3.5%), or the opposite correlation (9/85 = 10.6%); possible reasons being different categorization of HPV viral load levels, or the use of specific sampling methods. Despite variations in study design and populations, the above findings suggest that HPV viral load is correlated to clinical outcome, and may become an important biomarker for treatment selection and response monitoring for cervical cancer.

Erratum: Acute cellular and vascular responses to photodynamic therapy using EGFR-targeted nanobody-photosensitizer conjugates studied with intravital optical imaging and magnetic resonance imaging: Erratum.

[This corrects the article DOI: 10.7150/thno.37949.].

Radiosensitization by Hyperthermia Critically Depends on the Time Interval.

PURPOSE: Hyperthermia is a potent sensitizer of radiation therapy that improves both tumor control and survival in women with locally advanced cervical cancer (LACC). The optimal sequence and interval between hyperthermia and radiation therapy are still under debate. METHODS AND MATERIALS: We investigated the interval and sequence in vitro in cervical cancer cell lines, patient-derived organoids, and SiHa cervical cancer hind leg xenografts in athymic nude mice and compared the results with retrospective results from 58 women with LACC treated with thermoradiotherapy. RESULTS: All 3 approaches confirmed that shortening the interval between hyperthermia and radiation therapy enhanced hyperthermic radiosensitization by 2 to 8 times more DNA double-strand breaks and apoptosis and 10 to 100 times lower cell survival, delayed tumor growth in mice, and increased the 5-year survival rate of women with LACC from 22% (interval ≥80 minutes) to 54% (interval <80 minutes). In vitro and in vivo results showed that the sequence of hyperthermia and radiation therapy did not affect the outcome. CONCLUSIONS: Shortening the interval between hyperthermia and radiation therapy significantly improves treatment outcomes. The sequence of hyperthermia and radiation therapy (before or after) does not seem to matter.

Core-shell inorganic NP@MOF nanostructures for targeted drug delivery and multimodal imaging-guided combination tumor treatment.

It is well known that metal-organic framework (MOF) nanostructures have unique characteristics such as high porosity, large surface areas and adjustable functionalities, so they are ideal candidates for developing drug delivery systems (DDSs) as well as theranostic platforms in cancer treatment. Despite the large number of MOF nanostructures that have been discovered, conventional MOF-derived nanosystems only have a single biofunctional MOF source with poor colloidal stability. Accordingly, developing core-shell MOF nanostructures with good colloidal stability is a useful method for generating efficient drug delivery, multimodal imaging and synergistic therapeutic systems. The preparation of core-shell MOF nanostructures has been done with a variety of materials, but inorganic nanoparticles (NPs) are highly effective for drug delivery and imaging-guided tumor treatment. Herein, we aimed to overview the synthesis of core-shell inorganic NP@MOF nanostructures followed by the application of core-shell MOFs derived from magnetic, quantum dots (QDs), gold (Au), and gadolinium (Gd) NPs in drug delivery and imaging-guided tumor treatment. Afterward, we surveyed different factors affecting prolonged drug delivery and cancer therapy, cellular uptake, biocompatibility, biodegradability, and enhanced permeation and retention (EPR) effect of core-shell MOFs. Last but not least, we discussed the challenges and the prospects of the field. We envision this article may hold great promise in providing valuable insights regarding the application of hybrid nanostructures as promising and potential candidates for multimodal imaging-guided combination cancer therapy.

Electrochemical aptasensor based on the engineered core-shell MOF nanostructures for the detection of tumor antigens.

It is essential to develop ultrasensitive biosensors for cancer detection and treatment monitoring. In the development of sensing platforms, metal-organic frameworks (MOFs) have received considerable attention as potential porous crystalline nanostructures. Core-shell MOF nanoparticles (NPs) have shown different diversities, complexities, and biological functionalities, as well as significant electrochemical (EC) properties and potential bio-affinity to aptamers. As a result, the developed core-shell MOF-based aptasensors serve as highly sensitive platforms for sensing cancer biomarkers with an extremely low limit of detection (LOD). This paper aimed to provide an overview of different strategies for improving selectivity, sensitivity, and signal strength of MOF nanostructures. Then, aptamers and aptamers-modified core-shell MOFs were reviewed to address their functionalization and application in biosensing platforms. Additionally, the application of core-shell MOF-assisted EC aptasensors for detection of several tumor antigens such as prostate-specific antigen (PSA), carbohydrate antigen 15-3 (CA15-3), carcinoembryonic antigen (CEA), human epidermal growth factor receptor-2 (HER2), cancer antigen 125 (CA-125), cytokeratin 19 fragment (CYFRA21-1), and other tumor markers were discussed. In conclusion, the present article reviews the advancement of potential biosensing platforms toward the detection of specific cancer biomarkers through the development of core-shell MOFs-based EC aptasensors.

The interaction mechanism of plasma iron transport protein transferrin with nanoparticles.

In the biological systems, exposure to nanoparticles (NPs) can cause complicated interactions with proteins, the formation of protein corona and structural changes to proteins. These changes depend not only on NP physicochemical properties, but also on the intrinsic stability of protein molecules. Although, the formation of protein corona on the surface of NPs and the underlying mechanisms have been fully explored in various studies, no comprehensive review has discussed the direct biochemical and biophysical interactions between NPs and blood proteins, particularly transferrin. In this review, we first discussed the interaction of NPs with proteins to comprehend the effects of physicochemical properties of NPs on protein structure. We then overviewed the transferrin structure and its direct interaction with NPs to explore transferrin stability and its iron ion (Fe3+) release behavior. Afterwards, we surveyed the various biological functions of transferrin, such as Fe3+ binding, receptor binding, antibacterial activity, growth, differentiation, and coagulation, followed by the application of transferrin-modified NPs in the development of drug delivery systems for cancer therapy. We believe that this study can provide useful insight into the design and development of bioconjugates containing NP-transferrin for potential biomedical applications.

HMGA2 regulation by miRNAs in cancer: Affecting cancer hallmarks and therapy response.

High mobility group A 2 (HMGA2) is a protein that modulates the structure of chromatin in the nucleus. Importantly, aberrant expression of HMGA2 occurs during carcinogenesis, and this protein is an upstream mediator of cancer hallmarks including evasion of apoptosis, proliferation, invasion, metastasis, and therapy resistance. HMGA2 targets critical signaling pathways such as Wnt/ß-catenin and mTOR in cancer cells. Therefore, suppression of HMGA2 function notably decreases cancer progression and improves outcome in patients. As HMGA2 is mainly oncogenic, targeting expression by non-coding RNAs (ncRNAs) is crucial to take into consideration since it affects HMGA2 function. MicroRNAs (miRNAs) belong to ncRNAs and are master regulators of vital cell processes, which affect all aspects of cancer hallmarks. Long ncRNAs (lncRNAs) and circular RNAs (circRNAs), other members of ncRNAs, are upstream mediators of miRNAs. The current review intends to discuss the importance of the miRNA/HMGA2 axis in modulation of various types of cancer, and mentions lncRNAs and circRNAs, which regulate this axis as upstream mediators. Finally, we discuss the effect of miRNAs and HMGA2 interactions on the response of cancer cells to therapy. Regarding the critical role of HMGA2 in regulation of critical signaling pathways in cancer cells, and considering the confirmed interaction between HMGA2 and one of the master regulators of cancer, miRNAs, targeting miRNA/HMGA2 axis in cancer therapy is promising and this could be the subject of future clinical trial experiments.

An In Vivo Model to Study Cell Migration in XYZ-T Dimension Followed by Whole-Mount Re-evaluation.

Cell migration is a very dynamic process involving several chemical as well as biological interactions with other cells and the environment. Several models exist to study cell migration ranging from simple 2D in vitro cultures to more demanding 3D multicellular assays, to complex evaluation in animals. High-resolution 4D (XYZ, spatial + T, time dimension) intravital imaging using transgenic animals with a fluorescent label in cells of interest is a powerful tool to study cell migration in the correct environment. Here we describe an advanced dorsal skinfold chamber model to study endothelial cell and pericyte migration and association.

Image-guided drug delivery in nanosystem-based cancer therapies.

The past decades have shown significant advancements in the development of solid tumor treatment. For instance, implementation of nanosystems for drug delivery has led to a reduction in side effects and improved delivery to the tumor region. However, clinical translation has faced challenges, as tumor drug levels are still considered to be inadequate. Interdisciplinary research has resulted in the development of more advanced drug delivery systems. These are coined "smart" due to the ability to be followed and actively manipulated in order to have better control over local drug release. Therefore, image-guided drug delivery can be a powerful strategy to improve drug activity at the target site. Being able to visualize the inflow of the administered smart nanosystem within the tumor gives the potential to determine the right moment to apply the facilitator to initiate drug release. Here we provide an overview of available nanosystems, imaging moieties, and imaging techniques. We discuss preclinical application of these smart drug delivery systems, the strength of image-guided drug delivery, and the future of personalized treatment.

Nano-bio interaction: An overview on the biochemical binding of DNA to inorganic nanoparticles for the development of anticancer and antibacterial nano-platforms.

It has long been known that inorganic nanoparticles (NPs) can interact with biological macromolecules and show a wider range of biomedical characteristics, including antibacterial, anticancer and antioxidant effects, which cannot be mimicked by their bulky counterparts. It is of great importance in their biomedical applications to study DNA damage in bacterial and cancer cells to develop biocompatible therapeutic nano-platforms derived from inorganic NPs. Therefore, to determine how DNA interacts with inorganic NPs serving as therapeutic agents, thermodynamic and structural studies are essential for an understanding of those mechanisms, thereby allowing for their modulation and manipulation of nano-bio interface. In this paper, we aimed to overview the biophysical techniques typically employ to study DNA-NP interactions as well as the mechanistic aspects of the interaction between different inorganic NPs and calf thymus DNA (CT-DNA), a well-known laboratory model, followed by a survey of different parameters affecting the interaction of NPs and DNA. The molecular interactions between inorganic NPs and DNA were then discussed in relation to their anticancer and antibacterial properties. As a final point, we discussed challenges and future perspectives to put forward the possible applications of the field. In conclusion, the interaction between NPs and DNA needs to be studied more deeply in order to develop potential NP-based anticancer and antibacterial platforms for future clinical applications.

Liposomal Drug Delivery Systems for Cancer Therapy: The Rotterdam Experience.

At the Nanomedicine Innovation Center (NICE) at the Erasmus MC in Rotterdam, we have approached the treatment of cancer by starting with a vision of first establishing a platform that enables us to overcome the low levels of drugs delivered to tumors and the issue of dose-limiting toxicity. Showing that a reduction of the volume of distribution, and a lowering of toxicity and side-effects, accompanied by augmented intratumoral drug delivery, could change outcomes in patients, paved the way to target, not only localized disease, but also systemic and metastasized cancers. In particular, the detailed studies with intravital microscopy we performed at NICE provided us with the necessary insights and affected to a large extent our program on liposome-based cancer therapy. Together with our experience with the loco-regional treatment of cancer, this helped us to develop a program that focused on the subsequent aspects discussed here. We recognized that passive accumulation of nanoparticles was not as effective as previously believed and undertook to improve the local accumulation by changing the tumor pathophysiology and, in particular, the vascular permeability. We added the targeting of liposomes using vascular and tumor directed moieties, to improve cellular drug delivery. To improve payload delivery, we studied the modification of liposomes with phospholipids that help passive drug release and augment cellular accumulation. Second, and importantly, modification of liposomes was undertaken, to enable triggered drug release. The capability for modifying liposomes to respond to a trigger, and the ability to now apply an external trigger (e.g., hyperthermia) and specifically reach the tumor volume, resulted in the current smart drug delivery systems. Our experience at NICE, after a few decades of research on lipid-based nanoparticles, shows that, after the first liposomal formulation registered for clinical application in cancer therapy, further developments quickly followed, while further clinical applications lagged behind. Now we need to focus on and make the next steps towards the clinic, to fulfil the promise that is found there.

Stealth nanoparticles in oncology: Facing the PEG dilemma.

Nanoparticles (Nps) have revolutionized the landscape of many treatments, by modifying not only pharmacokinetic properties of the encapsulated agent, but also providing a significant protection of the drug from non-desired interactions, and reducing side-effects of the enclosed therapeutic, enabling co-encapsulation of possibly synergistic compounds or activities, allowing a controlled release of content and improving the therapeutic effect. Nevertheless, in systemic circulation, Nps suffer a rapid removal by opsonisation and the action of Mononuclear phagocyte system (MPS). To overcome this problem, different polymers, in particular Polyethyleneglycol (PEG), have been used to cover the surface of these nanocarriers forming a hydrophilic layer that allows the delay of the removal. These advantages contrast with some drawbacks such as the difficulty to interact with cell membranes and the development of immunological reactions, conforming the known, "PEG dilemma". To address and minimize this phenomenon, different strategies have been applied. Therefore, this review aims to summarize the state of the art of Pegylation strategies, comment in depth on the principal characteristics of PEG and describe the main alternatives, which are the use of cleavable PEG, addition of different polymers or even use other derivatives of cell membranes to camouflage Nps.

Temperature-sensitive polymers to promote heat-triggered drug release from liposomes: Towards bypassing EPR.

Heat-triggered drug release from temperature-sensitive nanocarriers upon the application of mild hyperthermia is a promising approach to achieve site-specific delivery of drugs. The combination of mild hyperthermia (41-42 °C) and temperature-sensitive liposomes (TSL) that undergo lipid phase-transition and drug release has been studied extensively and has shown promising therapeutic outcome in a variety of animal tumor models as well as initial indications of success in humans. Sensitization of liposomes to mild hyperthermia by means of exploiting the thermal behavior of temperature-sensitive polymers (TSP) provides novel opportunities. Recently, TSP-modified liposomes (TSPL) have shown potential for enhancing tumor-directed drug delivery, either by triggered drug release or by triggered cell interactions in response to heat. In this review, we describe different classes of TSPL, and analyze and discuss the mechanisms and kinetics of content release from TSPL in response to local heating. In addition, the impact of lipid composition, polymer and copolymer characteristics, serum components and PEGylation on the mechanism of content release and TSPL performance is addressed. This is done from the perspective of rationally designing TSPL, with the overall goal of conceiving efficient strategies to increase the efficacy of TSPL plus hyperthermia to improve the outcome of targeted anticancer therapy.

Criteria, Challenges, and Opportunities for Acellularized Allogeneic/Xenogeneic Bone Grafts in Bone Repairing.

As bone grafts become more commonly needed by patients and as donors become scarcer, acellularized bone grafts (ABGs) are becoming more popular for restorative purposes. While autogeneic grafts are reliable as a gold standard, allogeneic and xenogeneic ABGs have been shown to be of particular interest due to the limited availability of autogeneic resources and reduced patient well-being in long-term surgeries. Because of the complete similarity of their structures with native bone, excellent mechanical properties, high biocompatibility, and similarities of biological behaviors (osteoinductive and osteoconductive) with local bones, successful outcomes of allogeneic and xenogeneic ABGs in both in vitro and in vivo research have raised hopes of repairing patients' bone injuries in clinical applications. However, clinical trials have been delayed due to a lack of standardized protocols pertaining to acellularization, cell seeding, maintenance, and diversity of ABG evaluation criteria. This study sought to uncover these factors by exploring the bone structures, ossification properties of ABGs, sources, benefits, and challenges of acellularization approaches (physical, chemical, and enzymatic), cell loading, and type of cells used and effects of each of the above items on the regenerative technologies. To gain a perspective on the repair and commercialization of products before implementing new research activities, this study describes the differences between ABGs created by various techniques and methods applied to them. With a comprehensive understanding of ABG behavior, future research focused on treating bone defects could provide a better way to combine the treatment approaches needed to treat bone defects.

Piperine-loaded electrospun nanofibers, an implantable anticancer controlled delivery system for postsurgical breast cancer treatment.

Tumorectomy followed by radiotherapy, hormone, and chemotherapy, are the current mainstays for breast cancer treatment. However, these strategies have systemic toxicities and limited treatment outcomes. Hence, there is a crucial need for a novel controlled release delivery system for implantation following tumor resection to effectively prevent recurrence. Here, we fabricated polycaprolactone (PCL)-based electrospun nanofibers containing piperine (PIP), known for chemopreventive and anticancer activities, and also evaluated the impact of collagen (Coll) incorporation into the matrices. In addition to physicochemical characterization such as morphology, hydrophilicity, drug content, release properties, and mechanical behaviors, fabricated nanofibers were investigated in terms of cytotoxicity and involved mechanisms in MCF-7 and 4T1 breast tumor cell lines. In vivo antitumor study was performed in 4T1 tumor-bearing mice. PIP-PCL75-Coll25 nanofiber was chosen as the optimum formulation due to sustained PIP release, good mechanical performance, and superior cytotoxicity. Demonstrating no organ toxicity, animal studies confirmed the superiority of locally administered PIP-PCL75-Coll25 nanofiber in terms of inhibition of growth tumor, induction of apoptosis, and reduction of cell proliferation compared to PIP suspension, blank nanofiber, and the control. Taken together, we concluded that PIP-loaded nanofibers can be introduced as a promising treatment for implantation upon breast tumorectomy.

Artificial engineering of the protein corona at bio-nano interfaces for improved cancer-targeted nanotherapy.

Nanoparticles (NPs) have been used in numerous applications as anticancer, antibacterial and antioxidant agents. Artificial engineering of protein interactions with NPs in biological systems is crucial to develop potential NPs for drug delivery and cancer nanotherapy. The protein corona (PC) on the NP surface, displays an interface between biomacromolecules and NPs, governing their pharmacokinetics and pharmacodynamics. Upon interaction of proteins with the NPs, their surface features are modified and they can easily be removed from the circulation by the mononuclear phagocytic system (MPS). PC properties heavily depend on the biological microenvironment and NP physicochemical parameters. Based on this context, we have surveyed different approaches that have been used for artificial engineering of the PC composition on NP surfaces. We discussed the effects of NP size, shape, surface modifications (PEGylation, self-peptide, other polymers), and protein pre-coating on the PC properties. Additionally, other factors including protein source and structure, intravenous injection and the subsequent shear flow, plasma protein gradients, temperature and local heat transfer, and washing media were considered in the context of their effects on the PC properties and overall target cellular effects. Moreover, the effects of NP-PC complexes on cancer cells based on cellular interactions, organization of intracellular PC (IPC), targeted drug delivery (TDD) and regulation of burst drug release profile of nanoplatforms, enhanced biocompatibility, and clinical applications were discussed followed by challenges and future perspective of the field. In conclusion, this paper can provide useful information to manipulate PC properties on the NP surface, thus trying to provide a literature survey to shorten their shipping from preclinical to clinical trials and to lay the basis for a personalized PC.

An Updated Review on EPR-Based Solid Tumor Targeting Nanocarriers for Cancer Treatment.

The enhanced permeability and retention (EPR) effect in cancer treatment is one of the key mechanisms that enables drug accumulation at the tumor site. However, despite a plethora of virus/inorganic/organic-based nanocarriers designed to rely on the EPR effect to effectively target tumors, most have failed in the clinic. It seems that the non-compliance of research activities with clinical trials, goals unrelated to the EPR effect, and lack of awareness of the impact of solid tumor structure and interactions on the performance of drug nanocarriers have intensified this dissatisfaction. As such, the asymmetric growth and structural complexity of solid tumors, physicochemical properties of drug nanocarriers, EPR analytical combination tools, and EPR description goals should be considered to improve EPR-based cancer therapeutics. This review provides valuable insights into the limitations of the EPR effect in therapeutic efficacy and reports crucial perspectives on how the EPR effect can be modulated to improve the therapeutic effects of nanomedicine.

Assessment of the In Vivo Response to Nanobody-Targeted PDT Through Intravital Microscopy.

Methods that allow real-time, longitudinal, intravital detection of the fluorescence distribution and the cellular and vascular responses within tumor and normal tissue are important tools to obtain valuable information when investigating new photosensitizers and photodynamic therapy (PDT) responses. Intravital confocal microscopy using the dorsal skinfold chamber model gives the opportunity to visualize and determine the distribution of photosensitizers within tumor and normal tissue. Next to that, it also allows the visualization of the effect of treatment with respect to changes in vascular diameter and blood flow, vascular leakage, and tissue necrosis, in the first days post-illumination. Here, we describe the preparation of the skinfold chamber model and the intravital microscopy techniques involved, for a strategy we recently introduced, that is, the nanobody-targeted PDT. In this particular approach, photosensitizers are conjugated to nanobodies to target these specifically to cancer cells.

An overview on the exploring the interaction of inorganic nanoparticles with microtubules for the advancement of cancer therapeutics.

Targeting microtubules (MTs), dynamic and stable proteins in cells, by different ligands have been reported to be a potential strategy to combat cancer cells. Inorganic nanoparticles (NPs) have been widely used as anticancer, antibacterial and free radical scavenging agents, where they come in contact with biological macromolecules. The interaction between the NPs and biological macromolecules like MTs frequently occurs through different mechanisms. A prerequisite for a detailed exploration of MT structures and functions for biomedical applications like cancer therapy is to investigate profoundly the mechanisms involved in MT-NP interactions, for which the full explanation and characterization of the parameters that are responsible for the formation of a NP-protein complex are crucial. Therefore, in view of the fact that the goal of the rational NP-based future drug design and new therapies is to rely on the information of the structural details and protein-NPs binding mechanisms to manipulate the process of developing new potential drugs, a comprehensive investigation of the essence of the molecular recognition/interaction is also of considerable importance. In the present review, first, the microtubule (MT) structure and its binding sites upon interaction with MT stabilizing agents (MSAs) and MT destabilizing agents (MDAs) are introduced and rationalized. Next, MT targeting in cancer therapy and interaction of NPs with MTs are discussed. Furthermore, interaction of NPs with proteins and the manipulation of protein corona (PC), experimental techniques and direct interaction of NPs with MTs, are discussed, and finally the challenges and future perspective of the field are introduced. We envision this review can provide useful information on the manipulation of the MT lattice for the progress of cancer nanomedicine.