Metal nanoclusters, made up of several to one hundred metal atoms (e.g., Au, Ag, Cu, Pt), are a novel class of intermediate between metal atoms and nanoparticles. As their size (<2 nm) borders on the Fermi wavelength of electrons, metal nanoclusters possess strong photoluminescence in comparison with large metal nanoparticles (>2 nm). This, combined with tunable fluorescence emissions, high photostability, good quantum yields and facile synthesis, make them excellent fluorescent labels for biomedical applications.
However, the reduction of metal ions in liquid solution during synthesis usually causes large nanoparticles rather than small metal nanocluster formation because of their tendency to aggregate. In light of this, proteins whose thiol, amino, and carboxyl groups have a strong affinity for metal atoms are typically used to stabilize metal nanoclusters to protect them from aggregationthese proctected clusters are commonly called protein-protected metal nanoclusters.
Protein-protected metal nanoclusters have excellent biocompatibility and have received considerable attention as a luminescent probe in a number of fields such as biosensing, bioimaging, and imaging-guided therapy. However, apart from unique optical properties, protein-protected metal nanoclusters also possess interesting biological properties such as enzyme-like activity similar to that of natural enzymes; until recently, this has been an overlooked quality that is starting to shine in basic research and practical applications.
Nanozymes is a new termed used to refer to nanomaterials with intrinsic enzyme-like activity. Since professor Yan and coworkers first discovered that nanoparticleswhich are traditionally assumed to be inertpossessed intrinsic enzyme-like activity, a substantial amount of work has focused on further developing and harnessing the advantageous properties of nanozymes, which include high catalytic ability, high stability, and low cost. Nowadays, more than 540 kinds of nanomaterials, which possess intrinsic enzymatic activity, have been reported from 350 laboratories in 30 countries and have been used in biological analysis, environmental treatment, as antibacterial agents, cancer therapy, and antioxidation therapy.
In a recent study published in WIREs Nanomedicine and Nanobiotechnology, Professor Xiyun Yan and Kelong Fan explore the newly developing field of biologically active protein-protected metal nanoclusters, namely those that possess peroxidase, oxidase, and catalase activities, and are consequently used for biological analysis and environmental treatment.
An intriguing example of this is bovine serum albumin-protected gold (Au) nanoclusters, which exhibit peroxidase enzymatic activity to catalyze the oxidation of colored organic substrates, which is currently carried out using natural peroxidases. This method showed an advantage over the natural peroxidase-based methods because bovine serum albumin-protected Au nanoclusters exhibited higher robustness and retained enzymatic activity over a wide range of pH and temperatures. In another example, lysozyme-protected platinum (Pt) nanoclusters exhibit oxidase enzymatic activity which has been applied to the oxidative degradation of pollutants, such as methylene blue in lake water.
The proteins themselves not only provide protection and stabilization during synthesis, but can also provide a myriad of other functions to the nanoclusters. Proteins have been shown to enable in vivo applications because of their enhanced biocompatibility. In fact, a protease-responsive sensor for in vivo disease monitoring was designed by utilizing the peroxidase activity of peptide-protected Au nanoclusters and their ultra-small size dependent tumor accumulation and renal clearance properties.
The sensor was developed using peptides which are the substrates/targets of disease related proteases as protective ligands to synthesis the Au nanoclusters nanozymes, which were then conjugated to a carrier. After reaching the site of disease, the sensor was disassembled in response to the dysregulated protease and the liberated Au nanoclusters were filtered through the kidneys and into urine to produce a rapid and sensitive colorimetric readout of diseases state. By employing different enzymatic substrate as protective ligands for Au nanoclusters, this modular approach could enable the rapid detection of a diverse range of diseases with dysregulated protease activities such as cancer, inflammation, and thrombosis.
These findings have extended the horizon of protein-protected metal nanoclusters properties as well as their application in various fields, says Kelong Fan. Furthermore, in the field of nanozymes, protein-protected metal nanoclusters have emerged as an outstanding new addition. Due to their ultra-small size (<2 nm), they usually have higher catalytic activity, more suitable size for in vivo application, better biocompatibility and photoluminescence in comparison with large size nanozymes. We think that ultra-small nanozymes based on protein-protected MNCs are on the verge of attracting great interest across various disciplines and will stimulate research in the fields of nanotechnology and biology.
Despite the advantages and advancedprogress in the development of protein-protected metal nanoclusters asultra-small nanozymes, there are still some challenges that need to be addressedin future work.
First, most researchers still only rely on bovine serum albumin as both the reducing agent and stabilizer. Since we know that protein-protected metal nanoclusters may retain the bioactivity of the protein ligand, it is necessary to explore methods for synthesizing other new protein-protected metal nanoclusters, which will widen the diagnostic and therapeutic applications of protein-protected metal nanoclusters nanozymes.
Second, there are six types of catalytic reactions in nature: oxidoreductases, transferases, hydrolases, isomerases, ligases, and lyases. Thus far, although many protein-protected metal nanoclusters have demonstrated enzyme activities they all are oxidoreductase-like activities such as peroxidase, oxidase, and catalase. Therefore, there is a ample room to develop other types of nanozymes based on protein-protected metal nanoclusters. In this regard, more understanding of the structures and catalytic mechanisms of protein-protected metal nanoclusters is required in addition to the deeper understanding on natural enzymes themselves.
Third, a considerable number of reports have suggested that ultra-small nanozymes based on protein-protected metal nanoclusters are promising tools for biological analysis. However, little is known about the therapeutic function of these ultra-small clusters in vivo despite their advantages of suitable size and good biocompatibility. It is well known that peroxidase, oxidase, and catalase are main enzymes in biological systems involved in the maintenance of redox homeostasis. Thus, more attention should be paid to the usage of these ultra-small nanozymes based on protein-protected metal nanoclusters as bio-catalysts in various human diseases involved in redox dysregulation such as cancer, inflammation, cardiovascular diseases. It is also possible to employ the products of redox nanozymes to treat other diseases, for example, use the toxic hydroxyl radicals produced by peroxidase nanozymes to treat bacterial infection.
Overall, there is still much room for future research and application of ultra-small nanozymes based on protein-protected metal nanoclusters. It is expected that the enzyme-like activity of protein-protected metal nanoclusters will certainly attract broader interests across various disciplines and stimulate research in the fields of nanotechnology and biology, making these emerging ultra-small nanozymes become novel multifunctional nanomaterials for a number of biomedical applications.
Kindly contributed by the authors.
The rest is here:
- What is Nanomedicine? : Center for Nanomedicine - March 31st, 2020
- Nanomedicine | medicine | Britannica - March 31st, 2020
- Nano Medicine: Meaning, Advantages and Disadvantages - March 31st, 2020
- Nanomedicine: Nanotechnology, Biology and Medicine ... - March 31st, 2020
- What Might be the Best Way to Delivery Nanoparticle Therapy for Cancer? - Genetic Engineering & Biotechnology News - March 31st, 2020
- Nano Healthcare Technology For Medical Equipment Market Business Opportunities, 2020 Trends, Challenges and Standardization, Research, Key Players and... - March 31st, 2020
- Global Healthcare Nanotechnology Market 2019 Present Status and Future Opportunities by Major Companies Typs and Applications 2024 - The Fuel Fox - March 31st, 2020
- Nanobiotix 2019 Q4 and Annual Revenues - BioSpace - February 29th, 2020
- Dying Of Flu, College Student Used Cellphone To Call 911. He Died When Police Couldn't Find His Location. - Kaiser Health News - February 29th, 2020
- Clene Nanomedicine Announces First Patient Dosed in the RESCUE-ALS Clinical Trial for the Treatment of Amyotrophic Lateral Sclerosis (ALS) with Lead... - January 25th, 2020
- Modifying ICCA with Trp-Phe-Phe to Enhance in vivo Activity and Form N | IJN - Dove Medical Press - January 25th, 2020
- Biomedical Applications of Zeolitic Nanoparticles, with an Emphasis on | IJN - Dove Medical Press - January 25th, 2020
- Nanocarriers for Stroke Therapy: Advances and Obstacles in Translating | IJN - Dove Medical Press - January 25th, 2020
- Healthcare Nanotechnology (Nanomedicine) Market Share, Size, Future Demand, Global Research, Top Leading Player, Emerging Trends and Forecast to 2015 ... - January 25th, 2020
- Advancells Group & IFC Concluded their 3-Day Workshop on Regenerative Medicine - Business Wire India - January 25th, 2020
- I asked Tanzanians about studying in China: here's what they said - The Conversation Africa - January 25th, 2020
- The Future Of Nano Medicine - January 19th, 2020
- New Approaches in Breast Cancer Therapy Through Green Nanotechnology a | IJN - Dove Medical Press - January 19th, 2020
- Controlled phage therapy hints at future alternative to antibiotics - New Atlas - January 19th, 2020
- A New Old Therapy - The UCSB Current - January 19th, 2020
- Most engineered nanoparticles enter tumours through cells not between them, U of T researchers find - News@UofT - January 19th, 2020
- Canterbury father and son's invention will revolutionise medical treatment - Stuff.co.nz - December 28th, 2019
- Rewind 2019: A Look Back at Significant Developments in Indian Science This Year - The Weather Channel - December 27th, 2019
- Electroplating method makes conductive nanostraws for injecting into and sampling from cells - Chemical & Engineering News - December 3rd, 2019
- Design and Synthesis of Gold-Gadolinium-Core-Shell Nanoparticles as Co | IJN - Dove Medical Press - December 3rd, 2019
- Biochips Technologies, Companies, Applications & Markets, 2028 - 94 Companies are Included Along with a Listing of 121 Collaborations Between... - December 3rd, 2019
- Invicro LLC Joins Accenture's INTIENT Network to Help Advance Innovation in Drug Discovery and Scientific Research - BioSpace - December 3rd, 2019
- Nanoparticle therapy shows promise for treatment of rare cancer - The Brown Daily Herald - November 22nd, 2019
- At 9.6% CAGR, Healthcare Nanotechnology Market Global Industry to Reach Valuation over 306100 Million USD by 2025 - Markets Gazette 24 - November 22nd, 2019
- Nanotherapies for Rheumatoid Arthritis: Advantages, Challenges, and Future Direction - Rheumatology Advisor - November 22nd, 2019
- World Pancreatic Cancer Day: increasing awareness and inspiring action - UNSW Newsroom - November 22nd, 2019
- Bankrupt biopharmas are rare. 2019 has some worried that's changing. - BioPharma Dive - November 22nd, 2019
- Healthcare Nanotechnology Market Needs and Demand Analysis 2019 to 2025 - The Chicago Sentinel - November 13th, 2019
- Medical equipment to be infection-free now, says study - Zee News - November 12th, 2019
- Advances in nanomedicine for the treatment of ankylosing spondylitis | IJN - Dove Medical Press - November 1st, 2019
- Market Share in Nanotechnology and Nanomedicine for Treatment of Viral Infections Could Reach Tens of Billion Dollars - P&T Community - November 1st, 2019
- A highly biocompatible and intravenous injectable hafnium oxide nanocrystal synthesized to enhance radiaotherapy efficacy for cancer treatment -... - November 1st, 2019
- Doheny and UCLA Stein Eye Institutes Welcome Kaustabh Ghosh, PhD, to the Scientific and Clinical Research Faculty - PRNewswire - November 1st, 2019
- SUNY Potsdam chemistry professor awarded grant from National Institutes of Health - NNY360 - October 1st, 2019
- Improving 131I Radioiodine Therapy By Hybrid Polymer-Grafted Gold Nano | IJN - Dove Medical Press - October 1st, 2019
- MagForce AG to host Lunch Symposium on Local Therapies in Malignant Gliomas during the 19th European Congress of Neurosurgery (EANS2019) - BioSpace - October 1st, 2019
- Synthetic networks with tunable responsiveness, biodegradation, and molecular recognition for precision medicine applications - Science Advances - October 1st, 2019
- Self-Assembly Of Retinoid Nanoparticles For Melanoma Therapy | IJN - Dove Medical Press - October 1st, 2019
- Nanomanipulator Market Upcoming Trends, Revenue, Key Manufactures and Competitive Analysis till 2025 - One Digi Click - October 1st, 2019
- First-of-its-kind trial in ALS spurs hope for brutal disease - BioPharma Dive - October 1st, 2019
- FBI Investigation Targets Trump Booster Peter Thiel’s VC Firm - September 14th, 2019
- YouTube Influencers Are Mentally Collapsing From Stress - September 14th, 2019
- Watch SpaceX Test Its Crew Dragon’s Escape System - September 14th, 2019
- MIT Team “Accidentally” Invents Blackest Material in Existence - September 14th, 2019
- A Driver Tricked Uber’s Algorithm, Sexually Assaulted a Passenger - September 14th, 2019
- Toyota Wants to Slather Solar Panels All Over Its Prius Hybrid - September 14th, 2019
- A Runaway Star Is Escaping a Black Hole at 1.2 Million MPH - September 14th, 2019
- Putin Critic Uses Drone to Save Hard Drives Before Police Raid - September 14th, 2019
- Airbus Planes Will Track How Often Passengers Go to the Bathroom - September 14th, 2019
- Watch a Robot Fish Fly by Shooting Water out of Its Rear - September 14th, 2019
- Residents Are Trying to Flee Russian Town Where Snow Turned Black - September 14th, 2019
- This Startup Will Send DNA From Your Spit to the Moon for $99 - September 14th, 2019
- Horrifying Study: Corpses Thrash Around For a Year After Death - September 14th, 2019
- French Gov Official Warns Facebook: Libra Is Not Welcome Here - September 14th, 2019
- Watch a Tesla Model X Blast Through Deep Flood Waters - September 14th, 2019
- Milky Way’s Giant Black Hole Lets out Two Giant, Radioactive Burps - September 14th, 2019
- Instagram Keeps Accidentally Flagging Fish Photos as Offensive - September 14th, 2019
- MIT Community Horrified by Famed Researcher’s Epstein Outburst - September 14th, 2019
- Unlike MIT, Harvard Cut Off Epstein Donations After Conviction - September 14th, 2019
- Can You Tell Which of These Models Is CGI? - May 28th, 2019
- We Asked an AI to Finish Real Elon Musk Tweets - May 28th, 2019
- Watch a Super-Strong Robot Dog Pull a Three-Ton Airplane - May 28th, 2019
- Asteroid Flying by Earth Is so Big It Has Its Own Moon - May 28th, 2019
- United Nations: Siri and Alexa Are Encouraging Misogyny - May 28th, 2019
- New Law Could End Robocalling Once and For All - May 28th, 2019
- Scientists Set New Temperature Record for Superconductivity - May 28th, 2019
- Elevate Your Leadership and Grow Your Business at Your Clouds Can 2019 - May 28th, 2019
- NASA’s Moon Mission Leader Just Quit After Only Six Weeks - May 28th, 2019
- Watch a Tesla in an Underground Tunnel Race One on the Street - May 28th, 2019
- SpaceX Just Unleashed 60 Starlink Satellites Into Orbit - May 28th, 2019
- Elon Musk Ridicules Jeff Bezos’ Plan For Space Colonies - May 28th, 2019
- See China’s Newly Unveiled Maglev Train - May 28th, 2019
- Here’s How NASA Prepares Its Spacecraft for Mars - May 28th, 2019
- This Robot Scans Preschoolers’ Faces Daily for Signs of Sickness - May 28th, 2019
- New Research: The Oceans Are Slowly Leaking Into the Earth - May 28th, 2019