Mitochondria-targeting photosensitizer-encapsulated amorphous nanocage as a bimodal reagent for drug delivery and biodiagnose in vitro

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

Complex metal nanostructures represent an exceptional category of materials characterized by distinct morphologies and physicochemical properties. Nanostructures with shape anisotropies, such as nanorods, nanostars, nanocages, and nanoprisms, are particularly appealing due to their tunable surface plasmon resonances, controllable surface chemistries, and effective targeting capabilities. These complex nanostructures can absorb light in the near-infrared, enabling noteworthy applications in nanomedicine, molecular imaging, and biology. The engineering of targeting abilities through surface modifications involving ligands, antibodies, peptides, and other agents potentiates their effects. Recent years have witnessed the development of innovative structures with diverse compositions, expanding their applications in biomedicine. These applications encompass targeted imaging, surface-enhanced Raman spectroscopy, near-infrared II imaging, catalytic therapy, photothermal therapy, and cancer treatment. This review seeks to provide the nanomedicine community with a thorough and informative overview of the evolving landscape of complex metal nanoparticle research, with a specific emphasis on their roles in imaging, cancer therapy, infectious diseases, and biofilm treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Diagnostic Tools > Diagnostic Nanodevices.

Photochemical behavior of biosupramolecular assemblies of photosensitizers, cucurbit[n]urils and albumins

Biosupramolecular assemblies combining cucurbit[n]urils (CB[n]s) and proteins for the targeted delivery of drugs have the potential to improve the photoactivity of photosensitizers used in the photodynamic therapy of cancer. Understanding the complexity of these systems and how it affects the properties of photosensitizers is the focus of this work. We used acridine orange (AO⁺) as a model photosensitizer and compared it with methylene blue (MB⁺) and a cationic porphyrin (TMPyP⁴⁺). Encapsulation of the photosensitizers into CB[n]s (n = 7, 8) modified their photoactivity. In particular, for AO⁺, the photo-oxidation of HSA was enhanced in the presence of CB[7]; meanwhile it was decreased when included into CB[8]. Accordingly, peroxide generation and protein fragmentation were also increased when AO⁺ was encapsulated into CB[7]. The triplet excited state lifetimes of all the photosensitizers were lengthened by their encapsulation into CB[n]s, while the singlet oxygen quantum yield was enhanced only for AO⁺ and TMPyP⁴⁺, but it decreased for MB⁺. The results obtained in this work prompt the necessity of further investigating these kinds of hybrid assemblies as drug delivery systems because of their possible applications in biomedicine.

Nanocaged platforms: modification, drug delivery and nanotoxicity. Opening synthetic cages to release the tiger

Nanocages (NCs) have emerged as a new class of drug-carriers, with a wide range of possibilities in multi-modality medical treatments and theranostics. Nanocages can overcome such limitations as high toxicity caused by anti-cancer chemotherapy or by the nanocarrier itself, due to their unique characteristics. These properties consist of: (1) a high loading-capacity (spacious interior); (2) a porous structure (analogous to openings between the bars of the cage); (3) enabling smart release (a key to unlock the cage); and (4) a low likelihood of unfavorable immune responses (the outside of the cage is safe). In this review, we cover different classes of NC structures such as virus-like particles (VLPs), protein NCs, DNA NCs, supramolecular nanosystems, hybrid metal-organic NCs, gold NCs, carbon-based NCs and silica NCs. Moreover, NC-assisted drug delivery including modification methods, drug immobilization, active targeting, and stimulus-responsive release mechanisms are discussed, highlighting the advantages, disadvantages and challenges. Finally, translation of NCs into clinical applications, and an up-to-date assessment of the nanotoxicology considerations of NCs are presented.

Modulating the photo-exciting process of photosensitizer to improve in vitro phototoxicity by preparing its self-assembly nanostructures

Self-assembled photosensitizer nanostructures preparation by controlling the charge property of drug and ion strength of environment to improve photodynamic activity.

Spectroscopic studies on the interaction of Ga3+-hypocrellin A with myoglobin

In this article, the interaction mechanism of Ga(3+)-hypocrellin A (Ga(3+)-HA) with myoglobin (Mb) is studied in detail through various spectroscopic technologies. UV-vis absorption and fluorescence spectra demonstrate the interaction process. The Stern-Volmer plot and the time-resolved fluorescence study suggest the fluorescence quenching mechanism of Mb by Ga(3+)-HA is a static quenching procedure, and the electronic transfer forces play a major role in binding Ga(3+)-HA to Mb. Furthermore, synchronous fluorescence studies and circular dichroism (CD) spectra reveal that the conformation of Mb is changed after its conjugation with Ga(3+)-HA.

External heavy-atomic construction of photosensitizer nanoparticles for enhanced in vitro photodynamic therapy of cancer

Introduction of heavy atoms around photosensitizers (PSs) generally facilitates intersystem crossing (ISC) and improves their quantum yield of singlet oxygen ((1)O(2)) generation ability, which is a key species in photodynamic therapy (PDT). Here, we report Pt(IV)- and Au(III)-modified silica nanoparticles (SN) as the drug delivery system of a hypocrellin A (HA) to improve its photodynamic activity through external heavy atom effect. Comparative studies with Pt- and Au-modified and unmodified nanoparticles have demonstrated that the intraparticle external heavy atom effect on the encapsulated HA molecules significantly enhances their efficiency of (1)O(2) generation and, thereby, the in vitro photodynamic efficacy to cancer cells. The results well elucidated the potential of our PSs/heavy metal ions doped nanocarrier for improving the actual efficacy of PDT.

Approaches for targeting mitochondria in cancer therapy

The recognition of the role that mitochondria play in human health and disease is evidenced by the emergence in recent decades of a whole new field of "Mitochondrial Medicine". Molecules located on or inside mitochondria are considered prime pharmacological targets and a wide range of efforts are underway to exploit these targets to develop targeted therapies for various diseases including cancer. However the concept of targeting, while seemingly simple in theory, has multiple subtly different practical approaches. The focus of this article is to highlight these differences in the context of a discussion on the current status of various mitochondria-targeted approaches to cancer therapy.