Hollow Nanomaterials in Advanced Drug Delivery Systems: From Single‐ to Multiple Shells

Abstract

Hollow‐structured nanomaterials (HSNMs) have attracted increased interest in biomedical fields, owing to their excellent potential as drug delivery systems (DDSs) for clinical applications. Among HSNMs, hollow multi‐shelled structures (HoMSs) exhibit properties such as high loading capacity, sequential drug release, and multi‐functionalized modification and represent a new class of nanoplatforms for clinical applications. The remarkable properties of HoMS‐based DDS can simultaneously satisfy and enhance DDSs for delivering small molecular drugs (e.g., antibiotics, chemotherapy drugs, and imaging agents) and macromolecular drugs (e.g., protein/peptide‐ and nucleic acid‐based drugs). First, the latest research advances in delivering small molecular drugs are summarized and highlight the inherent advantages of HoMS‐based DDSs for small molecular drug targeting, combining continuous therapeutic drug delivery and theranostics to optimize the clinical benefit. Meanwhile, the macromolecular drugs DDSs are in the initial development stage and currently offer limited delivery modes. There is a growing need to analyze the deficiency of other HSNMs and integrate the advantages of HSNMs, providing solutions for the safe, stable, and cascade delivery of macromolecular drugs to meet vast treatment requirements. Therefore, the latest advances in HoMS‐based DDSs are comprehensively reviewed, mainly focusing on the characteristics, research progress by drug category, and future research prospects.

Bacteriophages as nanocarriers for targeted drug delivery and enhanced therapeutic effects

“…In antigen-antibody display, bacteriophage T4 has been extensively employed, most involving the two 2 highly antigenic outer capsid (Hoc) and small outer capsid (Soc) proteins that bind to localised capsid sites. 103…”

“…1 They are primarily aimed at improving therapeutic efficacy by providing the optimal or sustained release of bioactive agents; reducing administration frequency; ensuring continuous drug supply at therapeutic levels; achieving the targeted/specific delivery of drugs to the site of action; enhancing drug localisation; reducing off-target effects, minimising side effects; enhancing safety via the minimisation of systemic exposure; protecting drugs against enzymatic degradation, pH and other environmental conditions; improving drug stability and bioavailability; and increasing patient and treatment compliance and adherence. 2–6…”

Metal‐Phenolic Network with Pd Nanoparticle Nodes Synergizes Oxidase‐Like and Photothermal Properties to Eradicate Oral Polymicrobial Biofilm‐Associated Infections

“…[4] Poor oral hygiene, antibiotic-based enzymes in our innate immune systems that can produce reactive oxygens species (ROS) to damage cell membranes and other biomacromolecules. [14][15][16][17][18] For instance, nanozymes with the peroxidase-or oxidase-like property are capable of converting hydrogen peroxide (H 2 O 2 ) or oxygen (O 2 ) into highly lethal reactive oxygen species (ROS, •OH, or •O 2 − ) to damage the bacterial cell membrane and biomacromolecules such as DNA and proteins, eventually leading to bacterial lysis. [19] However, some pathogens, such as C. albicans, could produce ROS-scavenging enzymes (such as catalases) and other redox-reactive molecules (thiols) for scavenging ROS, [20][21][22] significantly hampering the efficiency of ROS-generating nanozymes in eradicating polymicrobial biofilms.…”

Seed-like Hollow Nanoparticles by a Dynamic Interfacial-Tension-Controlled Polar Growth Strategy

“…Natural marvelous designs and wealth living organisms with various morphologies have long been a source of inspiration for developing bionic nanomaterials. − Seed-like structures have attracted considerable attention because of their anisotropic elliptical, obovate, and rhomboid geometries. , However, successfully manufacturing these structures on the nanoscale remains challenging. Additionally, hollow nanostructures offer substantial potential for various applications, such as storage, encapsulation, nanoreactor, and nanomotor applications, owing to their low density, large surface area, and utilizable voids. − However, the existing hollow nanostructures are primarily spherical. Recently, some progress has been achieved in synthesizing anisotropic hollow nanostructures using template, − swelling–deswelling, − and anisotropic fusion strategies. − However, developing an effective growth mechanism for synthesizing seed-like hollow nanoparticles (SHNPs) with tailored structures still remains challenging.…”