METTL3-dependent N6-methyladenosine modification is involved in berberine-mediated neuroprotection in ischemic stroke by enhancing the stability of NEAT1 in astrocytes.

Ischemic stroke (IS) is one of the principal causes of disability and death worldwide. Berberine (BBR), derived from the traditional Chinese herbal medicine Huang Lian, has been reported to inhibit the progression of stroke, but the specific mechanism whereby BBR modulates the progression of ischemic stroke remains unclear. N6-methyladenosine (m6A) modification is the most typical epigenetic modification of mRNA post-transcriptional modifications, among which METTL3 is the most common methylation transferase. During the study, the middle cerebral artery occlusion/reperfusion (MCAO/R) was established in mice, and the mice primary astrocytes and neurons induced by oxygen-glucose deprivation/reoxygenation (OGD/R) was simulated in vitro. Level of LncNEAT1, miR-377-3p was detected via RT-qPCR. The levels of Nampt and METTL3 were measured by Western blot. CCK8 and LDH assay was performed to detect cell viability. Here, we found that berberine alleviates MCAO/R-induced ischemic injury and up-regulates the expression of Nampt in astrocytes, miR-377-3p inhibits the expression of Nampt in astrocytes after OGD/R, thus promoting neuronal injury. NEAT1 binds to miR-377-3p in OGD/R astrocytes and plays a neuronal protective role as a ceRNA. METTL3 can enhance NEAT1 stability in OGD/R astrocytes by modulating m6A modification of NEAT1. Taken together, our results demonstrate that berberine exerts neuroprotective effects via the m6A methyltransferase METTL3, which regulates the NEAT1/miR-377-3p/Nampt axis in mouse astrocytes to ameliorate cerebral ischemia/reperfusion (I/R) injury.

Intratumor delivery of amino-modified graphene oxide as a multifunctional photothermal agent for efficient antitumor phototherapy.

Due to the high selectivity and non-invasive property, phototherapy has attracted increasing attention in the treatment of cancer. Targeted delivery and retention of photoactive agents in tumor tissue is of great significance and importance for safe and efficient phototherapy. Herein, we report a multifunctional nanomaterial photothermal agent, namely amino-modified graphene oxide (AGO) for anti-oral cancer photothermal therapy (PTT). Compared to the parental graphene oxide (GO) which has a negative charge and weak photothermal effect, AGO possesses a positive charge (∼+50 mV) and the significantly enhanced photothermal effect. Positive charge allows AGO to efficiently interact with tumor cells and retain in tumor tissue after intratumor injection. The enhanced photothermal effect allows AGO to achieve the tunable and efficient PTT. In vitro results show that AGO (15 µg/mL) reduces the viability of HSC-3 cells (oral squamous cell carcinoma cell line) to 5% under near infrared (NIR) irradiation (temperature increased to 58.4 °C). In vivo antitumor study shows that intratumor delivery of AGO (200 µg/mouse) has no inhibition effects on tumor growth (454% of initial tumor size) without NIR. With a single dose of NIR irradiation, however, AGO significantly reduces the tumor size to 25% of initial size in 1 of 4 mice, and even induces the complete tumor ablation in 3 of 4 mice. Furthermore, the injected AGO falls off along with the scab after PTT. Our findings indicate that AGO is a potential nano-photothermal agent for tunable, convenient and efficient anticancer PTT.

Synthesis, characterization, biological activity, and in vitro digestion of selenium nanoparticles stabilized by Antarctic ice microalgae polypeptide.

A new type of uniformly dispersed selenium nanoparticles (SeNPs) was prepared using Antarctic ice microalgae polypeptides (AIMP) as the stabilizer and dispersant. Different characterization techniques and tests show that the SeNPs are effectively combined with AIMP through physical adsorption and hydrogen bonding to form a more stable structure. Orange-red, zero-valence, amorphous, and spherical AIMP-SeNPs with a diameter of 52.07 ± 1.011 nm and a zeta potential of -41.41 ± 0.882 mV were successfully prepared under the optimal conditions. The AIMP-SeNPs had significantly higher DPPH, ABTS and hydroxyl radicals scavenging abilities compared with AIMP and Na2SeO3, and prevented the growth of both Gram-negative and Gram-positive bacteria by disrupting the integrity of cell walls, cell membranes and mitochondrial membranes. The AIMP-SeNPs had higher gastrointestinal stability compared with SeNPs. Thus, this research highlights the crucial role of AIMP as a biopolymer framework in the dispersion, stabilization, and size management of SeNPs and concludes that AIMP-SeNPs can be exploited as a potent antioxidant supplement and antibacterial substance in foods and medicine.

Photothermal and natural activity-based synergistic antibacterial effects of Ti3C2Tx MXene-loaded chitosan hydrogel against methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) has strong resistance to antibiotic therapy. In this regard, developing antibiotic-free antibacterial agents is of great significance to treat MRSA infections. Herein, we loaded Ti3C2Tx MXene nanomaterial in the non-crosslinked chitosan (CS) hydrogel. The obtained MX-CS hydrogel is expected to not only adsorb MRSA cells via CS-MRSA interactions, but also gather the MXene-induced photothermal hyperthermia, achieving the efficient and intensive anti-MRSA photothermal therapy. As a result, under NIR irradiation (808 nm, 1.6 W/cm2, 5 min), MX-CS showed a greater photothermal effect than MXene alone did (30 µg/mL, 49.9 °C for MX-CS and 46.5 °C for MXene). Importantly, MRSA cells were rapidly adsorbed on MX-CS hydrogel (containing 30 µg/mL MXene) and completely inhibited (99.18 %) under NIR irradiation for 5 min. In contrast, MXene (30 µg/mL) and CS hydrogel alone only inhibited 64.52 % and 23.72 % MRSA, respectively, significantly lower than the inhibition caused by MX-CS (P < 0.001). Interestingly, when the hyperthermia was depleted by a 37 °C water bath, the bacterial inhibition rate of MX-CS significantly decreased to 24.65 %. In conclusion, MX-CS hydrogel has a remarkable synergistic anti-MRSA activity by gathering MRSA cells and MXene-induced hyperthermia, and may have great potentials in treating MRSA-infected diseases.

Nanomaterials-mediated photodynamic therapy and its applications in treating oral diseases.

Oral diseases, such as dental caries, periodontitis and oral cancer, have a very high morbidity over the world. Basically, many oral diseases are commonly related to bacterial infections or cell malignant proliferation, and usually located on the superficial positions. These features allow the convenient and efficient application of photodynamic therapy (PDT) for oral diseases, since PDT is ideally suitable for the diseases on superficial sites and has been widely used for antimicrobial and anticancer therapy. Photosensitizers (PSs) are an essential element in PDT, which induce the generation of a large number of reactive oxygen species (ROS) upon absorption of specific lights. Almost all the PSs are small molecules and commonly suffered from various problems in the PDT environment, such as low solubility and poor stability. Recently, reports on the nanomedicine-based PDT have been well documented. Various functionalized nanomaterials can serve either as the PSs carriers or the direct PSs, thus enhancing the PDT efficacy. Herein, we aim to provide a comprehensive understanding of the features of different oral diseases and discuss the potential applications of nanomedicine-based PDT in the treatment of some common oral diseases. Also, the concerns and possible solutions for nanomaterials-mediated PDT are discussed.

Nanomaterials-based photosensitizers and delivery systems for photodynamic cancer therapy.

The increasing cancer morbidity and mortality requires the development of high-efficiency and low-toxicity anticancer approaches. In recent years, photodynamic therapy (PDT) has attracted much attention in cancer therapy due to its non-invasive features and low side effects. Photosensitizer (PS) is one of the key factors of PDT, and its successful delivery largely determines the outcome of PDT. Although a few PS molecules have been approved for clinical use, PDT is still limited by the low stability and poor tumor targeting capacity of PSs. Various nanomaterial systems have shown great potentials in improving PDT, such as metal nanoparticles, graphene-based nanomaterials, liposomes, ROS-sensitive nanocarriers and supramolecular nanomaterials. The small molecular PSs can be loaded in functional nanomaterials to enhance the PS stability and tumor targeted delivery, and some functionalized nanomaterials themselves can be directly used as PSs. Herein, we aim to provide a comprehensive understanding of PDT, and summarize the recent progress of nanomaterials-based PSs and delivery systems in anticancer PDT. In addition, the concerns of nanomaterials-based PDT including low tumor targeting capacity, limited light penetration, hypoxia and nonspecific protein corona formation are discussed. The possible solutions to these concerns are also discussed.

Ti3C2Tx MXene loaded with indocyanine green for synergistic photothermal and photodynamic therapy for drug-resistant bacterium.

Infections caused by antibiotic-resistant bacteria are a critical threat to human health. Considering the difficulties and time-consuming nature of synthesizing new antibiotics, it is of great significance and importance to develop the antibiotic-independent antibacterial approaches against drug-resistant bacteria. Nanomaterials-based photothermal therapy (PTT) and photodynamic therapy (PDT) have attracted much attention due to their broad-spectrum bactericidal activity, low toxicity, and drug-free feature. In this work, we loaded indocyanine green (ICG) on the Ti3C2Tx MXene nanosheets (454 nm) so as to combine the photothermal effect of MXene with the photodynamic effect of ICG. Without near-infrared (NIR) irradiation, MXene (20 µg/mL), ICG (5 µg/mL) or ICG-loaded MXene (ICG-MXene) showed no significant antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Under NIR, however, the viability loss of MRSA remarkably increased to 45% for MXene, 66% for ICG and 100% for ICG-MXene. We further found that the great anti-MRSA activity of ICG-MXene under NIR was attributed to the combination of photothermal effect of MXene (high temperature) and photodynamic effect of ICG (high level of reactive oxygen species). Our findings indicate that MXene can be used as both the photothermal agent and the carrier of photosensitizers to achieve the synergistic PTT/PDT therapy for bacterial infections.

Size-dependent photothermal antibacterial activity of Ti3C2Tx MXene nanosheets against methicillin-resistant Staphylococcus aureus.

Developing antibiotics-independent antibacterial materials is of great importance for combating drug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). MXene (transition metal carbides and nitrides), a class of novel 2D nanomaterials, has shown great potentials in biomedical areas. However, the effect of MXene size on its properties and bioactivity is still unknown. Herein, we report for the first time that the antibacterial photothermal therapy efficacy of Ti3C2Tx MXene nanosheets is size-dependent. Three MXene suspensions with small size of 196 nm (MX-s), medium size of 347 nm (MX-m) and large size of 497 nm (MX-l) were prepared via ultrasonication. Upon NIR irradiation for 5 min, the temperature of MXene suspensions (10 µg/mL) increased to 64, 60 and 56 °C for MX-s, MX-m and MX-l, respectively. Accordingly, the viability loss of MRSA induced by MX-s, MX-m and MX-l under NIR was 93%, 69% and 56%, respectively. The in vivo study in the MRSA-infected mouse model showed that the photothermal therapy efficacy of MX-s was comparable to that of the positive control vancomycin. This is the first report on the size-dependent photothermal effect and photothermal antibacterial activity of MXene, which may guide the development of MXene-based therapeutics in the future. In addition, the drug-free antibacterial therapy has great implications for the treatment of antibiotics-resistant bacteria infections.

Potentials of nanotechnology in treatment of methicillin-resistant Staphylococcus aureus.

Abuse of antibiotics has led to the emergence of drug-resistant pathogens. Methicillin-resistant Staphylococcus aureus (MRSA) was reported just two years after the clinical use of methicillin, which can cause severe infections with high morbidity and mortality in both community and hospital. The treatment of MRSA infection is greatly challenging since it has developed the resistance to almost all types of antibiotics. As such, it is of great significance and importance to develop novel therapeutic approaches. The fast development of nanotechnology provides a promising solution to this dilemma. Functional nanomaterials and nanoparticles can act either as drug carriers or as antibacterial agents for antibacterial therapy. Herein, we aim to provide a comprehensive understanding of the drug resistance mechanisms of MRSA and discuss the potential applications of some functionalized nanomaterials in anti-MRSA therapy. Also, the concerns and possible solutions for the nanomaterials-based anti-MRSA therapy are discussed.

Curcumin- and Cyclopamine-Loaded Liposomes to Enhance Therapeutic Efficacy Against Hepatic Fibrosis.

BACKGROUND AND PURPOSE: Hepatic fibrosis is a public health problem characterized by activation of hepatic stellate cells (HSCs), which triggers excessive production of extracellular matrix (ECM). Inhibition of HSC activation may be an effective treatment. Since various pathways control HSC activation, a combination of drugs with different mechanisms may be more effective than monotherapy. METHODS: Here, we prepared liposomes loaded with curcumin and cyclopamine to inhibit HSC activation. We systematically analyzed the physicochemical characteristics of liposomes loaded with the two drugs, as well as their effects on HSC proliferation, activation and collagen production on gene, protein and cellular levels. RESULTS: The prepared liposomes helped solubilize both drugs, contributing to their uptake by cells. Liposomes loaded with both drugs inhibited cell proliferation, migration and invasion, as well as induced more apoptosis and perturbed the cell cycle more than the free combination of both drugs in solution or liposomes loaded with either drug alone. Liposomes loaded with both drugs strongly suppressed HSC activation and collagen secretion. CONCLUSION: Our results suggest that liposome encapsulation can increase the uptake of curcumin and cyclopamine as well as the synergism between them in anti-fibrosis. This approach shows potential for treating hepatic fibrosis.

Nanomaterials-based photothermal therapy and its potentials in antibacterial treatment.

With the prevalence of antibiotic-resistant bacteria, novel antibacterial strategies are urgently needed. In recent years, several antibiotics-independent physical approaches have attracted high attention and interests. Among those approaches, photothermal therapy (PTT), a novel non-invasive therapeutic technique, has exhibited great potentials in dealing with drug-resistant bacteria and bacterial biofilms. Photothermal agents (PTAs), which are either nanomaterials themselves or small molecules loaded in nanoparticles, are the essential element for PTT. How to deliver PTAs in a controlled manner is of great importance for high-efficiency and low-toxicity PTT. Therefore, a comprehensive understanding of various PTAs is required for the better application of PTT in antibacterial treatment. Herein, the physicochemical properties and antibacterial PTT of five types of PTAs are summarized. In addition, the PTT-involved multifunctional theranostics nanoplatforms and the potential approaches for reducing the side effects of PTT (such as targeted delivery and controlled release of PTAs) are also discussed.

Optimization of Alkali Extraction and Properties of Polysaccharides from Ziziphus jujuba cv. Residue.

Ziziphus jujuba cv. Muzao is a plant widely cultivated in the Yellow River Basin of China. It has nutritional and healthcare functions, in which polysaccharides are the main components of its bio-functions. In order to make effective use of Ziziphus jujuba cv. Muzao residue resources and explore new functional food ingredients, the polysaccharide (ZJRP) from Ziziphus jujuba cv. Muzao residues were extracted by sodium hydroxide, and the optimal extraction conditions of ZJRP were obtained by the response surface method. The basic composition and antioxidant effects of ZJRP were determined. The results showed that ZJRP has significant antioxidant activity, mainly reflected in the high DPPH radical scavenging rate, which may be related to their high content of galacturonic acid and the extraction method. In addition, the rheological and thermal properties of ZJRP were respectively determined by a rheometer and differential scanning calorimetry (DSC), indicating that they have shear thinning properties and good thermal stability. Results showed that the alkaline extraction method can be used as a potential technique for extracting ZJRP with high antioxidant activity, and ZJRP can be further explored as a functional food ingredient.

A mini-review of isolation, chemical properties and bioactivities of polysaccharides from buckwheat (Fagopyrum Mill).

Recently, there has an increased focus on the isolation, chemical properties and bioactivities of polysaccharides from buckwheat (Fagopyrum Mill), which is a member of the Polygonaceae family. Phytochemical and pharmacological studies have shown that polysaccharides are important biologically-active components of buckwheat, with numerous biological activities, including antioxidant, antitumor, immunomodulatory, antihypertensive and hypoglycemic effects. The purpose of this mini-review is to appraise available literature describing the extraction, separation, purification, structural characterization and biological activities of polysaccharides isolated from buckwheat. This mini-review also provides a foundation for the further investigation, production and application of buckwheat polysaccharides as functional foods and therapeutic agents.

Graphene-based nanomaterials and their potentials in advanced drug delivery and cancer therapy.

The continuing increase of cancer morbidity and death rate requires efficient therapeutic strategies. The traditional chemotherapy usually fails to treat cancer or prolong survival rate due to its toxicity to normal cells, side effects and lack of targeting capacity. In recent years, nanomaterials have shown great potentials to treat various cancers efficiently. Graphene-based nanomaterials, especially graphene oxide (GO) and reduced GO (rGO), have arisen as promising candidates for cancer therapy. Due to their unique physicochemical and optical properties including the extremely large surface area, modifiable active groups, great biocompatibility and strong photothermal effect, they can act either as tunable carriers or active agents for advanced chemotherapeutics delivery and cancer therapy. Therefore, combing the photothermal therapy, targeted drug delivery and chemotherapy would have great potentials for efficient cancer therapy. Herein, the comprehensive understandings of the physicochemical properties and various anti-cancer applications of GO and rGO as drug delivery systems or photothermal agents are described. Also, the concerns in using GO and rGO, such as the nano-protein interaction, and possible solutions are discussed.

Antibiofilm effect of drug-free and cationic poly(D,L-lactide-co-glycolide) nanoparticles via nano-bacteria interactions.

AIM: Recently, nano-bio interactions and their biomedical impacts have drawn much attention, but nano-bacteria interaction and its function are unknown. Herein, we aim to synthesize drug-free and cationic nanoparticles (CNPs) and investigate CNP-bacteria interaction and its antibiofilm effect. MATERIALS & METHODS: The bioactivity of CNPs against Streptococcus mutans was examined by colony-forming units counting and scanning electron microscopy. CNP-bacteria interaction force was measured by atomic force microscopy. RESULTS: CNPs (217.7 nm, 14.7 mv) showed a concentration-dependent activity against bacteria. Particularly, CNPs at 200 µg/ml completely inhibited planktonic bacterial growth and biofilm formation, and disrupted ∼70% mature biofilm. CNP-bacteria interaction force was up to 184 nN. CONCLUSION: CNPs have great potentials for convenient local use for prevention and treatment of bacteria-related oral diseases.

Highly Efficient Nonfullerene Polymer Solar Cells Enabled by a Copper(I) Coordination Strategy Employing a 1,3,4-Oxadiazole-Containing Wide-Bandgap Copolymer Donor.

A novel wide-bandgap copolymer of PBDT-ODZ based on benzo[1,2-b:4,5-b' ]dithiophene (BDT) and 1,3,4-oxadiazole (ODZ) blocks is developed for efficient nonfullerene polymer solar cells (NF-PSCs). PBDT-ODZ exhibits a wide bandgap of 2.12 eV and a low-lying highest occupied molecular orbital (HOMO) level of -5.68 eV, which could match well with the low-bandgap acceptor of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylthienyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']-dithiophene (ITIC-Th), inducing a good complementary absorption from 300 to 800 nm and a minimal HOMO level offset (0.1 eV). The PBDT-ODZ:ITIC-Th devices exhibit a large open-circuit voltage (Voc ) of 1.08 eV and a low energy loss (Eloss ) of 0.50 eV, delivering a high power conversion efficiency (PCE) of 10.12%. By adding a small amount of copper(I) iodide (CuI) as an additive to form coordination complexes in the active blends, much higher device performances are achieved due to the improved absorption and crystallinity. After incorporating 4% of CuI, the PCE is elevated to 12.34%, with a Voc of 1.06 V, a Jsc of 17.1 mA cm-2 and a fill factor of 68.1%. This work not only provides a novel oxadiazole-containing wide-bandgap polymeric donor candidate for high-performance NF-PSCs but also presents an efficient morphology-optimization approach to elevate the PCE of NF-PSCs for future practical applications.

White coat effect in hypertensive patients: the role of hospital environment or physician presence.

This study was to evaluate the role of hospital environment or physician presence for white coat effect (WCE) in hypertensive patients. At first, 54 hypertensive outpatients diagnosed on office blood pressure (OBP) were included for 2-week placebo run in. During the second week of the run in period, home BP was measured using electronic BP monitors for 5-7 days. Finally, 26 sustained hypertensive patients with home systolic BP/diastolic BP over 135/85 (but <180/110) mm Hg were enrolled for 8-week treatment of nifedipine controlled-release tablet. In the visit day, BP was measured by patient-self (OBP-p) or by doctor (OBP-d) according to order determined with randomization method. The self-BP measurement was performed in a reception room of hospital. The differences between home BP and OBP-d or OBP-p were calculated as WCE calculated on doctor-measurement (WCE-d) or WCE calculated on patient-measurement (WCE-p), respectively. The home and OBP were measured with the same BP device for each patient during the study period. In the total 54 outpatients received placebo, the WCE-d was similar to the WCE-p (for systolic BP 6.6 ± 14.4 vs. 6.8 ± 15.8 mm Hg, NS; for diastolic BP 3.3 ± 8.8 vs. 2.9 ± 9.2 mm Hg, NS). Meanwhile, the 26 sustained hypertensive patients had similar systolic WCE-d and WCE-p (4.8 ± 10.3 vs. 5.0 ± 12.2 mm Hg, NS) at placebo stage. Similarly, these values were comparable (3.0 ± 14.0 vs. 2.2 ± 14.4 mm Hg, NS) in treatment stage. Hospital environment plays a main role for the WCE in hypertensive patients.

Isolation, structures and bioactivities of the polysaccharides from jujube fruit (Ziziphus jujuba Mill.): A review.

Jujube (Ziziphus Jujuba Mill.) has been eaten as a fruit and nutraceutical food in China for thousands of years. Recent phytochemical and pharmacological studies have shown that the polysaccharides are one of major biologically active components of the jujube fruit and have various biological effects, including immunomodulatory, antioxidant, antitumor, hepatoprotective, and hypoglycemic activities, and gastrointestinal-protective effects. Although the extraction and purification of jujube polysaccharides are tedious processes, including different steps of liquid- and solid-phase separation, the polysaccharides have been structurally characterized. However, the relationships between the structures and activities of the jujube polysaccharides are not well established. The purpose of the present review is to appraise the previous and current literature on the extraction, purification, structural characterization, and biological activities of jujube polysaccharides. This review should provide a useful bibliography for the further investigation, production, and application of jujube polysaccharides in functional foods and therapeutic agents.

A Selenium-Modified Ginseng Polysaccharide Promotes the Apoptosis in Human Promyelocytic Leukemia (HL-60) Cells via a Mitochondrial-Mediated Pathway.

A ginseng polysaccharide was extracted, purified, and modified by nitric acid-selenious acid (HNO3-H2SeO3) method to yield one selenylation-modified polysaccharide (sGP). We reported for the first time the anticancer potential of sGP on the human promyelocytic leukemia HL-60 cell line and evaluated its relevant underlying mechanism. Our results showed that sGP markedly inhibited the growth of HL-60 cells via induction of apoptosis. The event of apoptosis was accompanied by the formation of apoptotic bodies; the release of cytochrome c; loss of mitochondrial membrane potential; and activation of caspase-9, caspase-3, and cleavage of poly ADP ribose polymerase (PARP) in HL-60 cells. In addition, western blot analysis showed that sGP inhibited antiapoptotic Bcl-2 protein expression and increased proapoptotic Bax protein expression in cells under identical conditions. Together, our study suggests that sGP induces apoptosis of HL-60 cells through the mitochondrial-dependent pathway.

Using interval maxima regression (IMR) to determine environmental optima controlling Microcystis spp. growth in Lake Taihu.

Fortnightly investigations at 12 sampling sites in Meiliang Bay and Gonghu Bay of Lake Taihu (China) were carried out from June to early November 2010. The relationship between abiotic factors and cell density of different Microcystis species was analyzed using the interval maxima regression (IMR) to determine the optimum temperature and nutrient concentrations for growth of different Microcystis species. Our results showed that cell density of all the Microcystis species increased along with the increase of water temperature, but Microcystis aeruginosa adapted to a wide range of temperatures. The optimum total dissolved nitrogen concentrations for M. aeruginosa, Microcystis wesenbergii, Microcystis ichthyoblabe, and unidentified Microcystis were 3.7, 2.0, 2.4, and 1.9 mg L(-1), respectively. The optimum total dissolved phosphorus concentrations for different species were M. wesenbergii (0.27 mg L(-1)) > M. aeruginosa (0.1 mg L(-1)) > M. ichthyoblabe (0.06 mg L(-1)) ≈ unidentified Microcystis, and the iron (Fe(3+)) concentrations were M. wesenbergii (0.73 mg L(-1)) > M. aeruginosa (0.42 mg L(-1)) > M. ichthyoblabe (0.35 mg L(-1)) > unidentified Microcystis (0.09 mg L(-1)). The above results suggest that if phosphorus concentration was reduced to 0.06 mg L(-1) or/and iron concentration was reduced to 0.35 mg L(-1) in Lake Taihu, the large colonial M. wesenbergii and M. aeruginosa would be replaced by small colonial M. ichthyoblabe and unidentified Microcystis. Thereafter, the intensity and frequency of the occurrence of Microcystis blooms would be reduced by changing Microcystis species composition.