The assembly and antitumor activity of lycium barbarum polysaccharide-platinum-based conjugates

Research Progress of Polysaccharide-Gold Nanocomplexes in Drug Delivery

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drug's effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Polysaccharide‑platinum complexes for cancer theranostics

Platinum anticancer drugs have been explored and developed in recent years to reduce systematic toxicities and resist drug resistance. Polysaccharides derived from nature have abundant structures as well as pharmacological activities. The review provides insights on the design, synthesis, characterization and associating therapeutic application of platinum complexes with polysaccharides that are classified by electronic charge. The complexes give birth to multifunctional properties with enhanced drug accumulation, improved tumor selectivity and achieved synergistic antitumor effect in cancer therapy. Several techniques developing polysaccharides-based carriers newly are also discussed. Moreover, the lasted immunoregulatory activities of innate immune reactions triggered by polysaccharides are summarized. Finally, we discuss the current shortcomings and outline potential strategies for improving platinum-based personalized cancer treatment. Using platinum-polysaccharides complexes for improving the immunotherapy efficiency represents a promising framework in future.

Versatile functionalization of pectic conjugate: From design to biomedical applications

Pectin exists extensively in nature and has attracted much attention in biological applications for its unique chemical and physical characteristics. Functionalized pectin, especially pectic conjugates, has given many possibilities for pectin to improve its properties and bioactivity as well as to deliver active molecules. To better exploit this strategy of pectic functionalization, this review presents in detail the structural modifications of pectin, different synthetic methods, and design strategies of pectic conjugates involving both traditional chemical and "green" approaches. Here, the research ideas and applications of pectic prodrugs as well as the development of preparation based on pectic conjugates are reviewed, with emphasis on crosslinking systems of functionalized pectin and nanosystems based on self-assembly techniques. We hope this review will provide comprehensive and valuable information for the functionalization and systematization of the pectic conjugate from synthesis to application.

Antioxidant Activities of Natural Polysaccharides and Their Derivatives for Biomedical and Medicinal Applications

Many chronic diseases such as Alzheimer's disease, diabetes, and cardiovascular diseases are closely related to in vivo oxidative stress caused by excessive reactive oxygen species (ROS). Natural polysaccharides, as a kind of biomacromolecule with good biocompatibility, have been widely used in biomedical and medicinal applications due to their superior antioxidant properties. In this review, scientometric analysis of the highly cited papers in the Web of Science (WOS) database finds that antioxidant activity is the most widely studied and popular among pharmacological effects of natural polysaccharides. The antioxidant mechanisms of natural polysaccharides mainly contain the regulation of signal transduction pathways, the activation of enzymes, and the scavenging of free radicals. We continuously discuss the antioxidant activities of natural polysaccharides and their derivatives. At the same time, we summarize their applications in the field of pharmaceutics/drug delivery, tissue engineering, and antimicrobial food additives/packaging materials. Overall, this review provides up-to-date information for the further development and application of natural polysaccharides with antioxidant activities.

Combined Photothermal Therapy and Lycium barbarum Polysaccharide for Topical Administration to Improve the Efficacy of Doxorubicin in the Treatment of Breast Cancer

In order to improve the efficacy of doxorubicin in the treatment of breast cancer, we constructed a drug delivery system combined with local administration of Lycium barbarum polysaccharides (LBP) and photothermal-material polypyrrole nanoparticles (PPY NPs). In vitro cytotoxicity experiments showed that the inhibitory effect of DOX + LBP + PPY NPs on 4T1 cells under NIR (near infrared) laser was eight times that of DOX at the same concentration (64% vs. 8%). In vivo antitumor experiments showed that the tumor inhibition rate of LBP + DOX + PPY NPs + NIR reached 87.86%. The results of the H&E staining and biochemical assays showed that the systemic toxicity of LBP + DOX + PPY NPs + NIR group was reduced, and liver damage was significantly lower in the combined topical administration group (ALT 54 ± 14.44 vs. 28 ± 3.56; AST 158 ± 16.39 vs. 111 ± 20.85) (p < 0.05). The results of the Elisa assay showed that LBP + DOX + PPY NPs + NIR can enhance efficacy and reduce toxicity (IL-10, IFN-γ, TNF-α, IgA, ROS). In conclusion, LBP + DOX + PPY NPs combined with photothermal therapy can improve the therapeutic effect of DOX on breast cancer and reduce its toxic side effects.

Herb Polysaccharide-Based Drug Delivery System: Fabrication, Properties, and Applications for Immunotherapy

Herb polysaccharides (HPS) have been studied extensively for their healthcare applications. Though the toxicity was not fully clarified, HPS were widely accepted for their biodegradability and biocompatibility. In addition, as carbohydrate polymers with a unique chemical composition, molecular weight, and functional group profile, HPS can be conjugated, cross-linked, and functionally modified. Thus, they are great candidates for the fabrication of drug delivery systems (DDS). HPS-based DDS (HPS-DDS) can bypass phagocytosis by the reticuloendothelial system, prevent the degradation of biomolecules, and increase the bioavailability of small molecules, thus exerting therapeutic effects. In this review, we focus on the application of HPS as components of immunoregulatory DDS. We summarize the principles governing the fabrication of HPS-DDS, including nanoparticles, micelles, liposomes, microemulsions, hydrogels, and microneedles. In addition, we discuss the role of HPS in DDS for immunotherapy. This comprehensive review provides valuable insights that could guide the design of effective HPS-DDS.

A new polysaccharide platform constructs self-adjuvant nanovaccines to enhance immune responses

Background

Nanovaccines have shown the promising potential in controlling and eradicating the threat of infectious diseases worldwide. There has been a great need in developing a versatile strategy to conveniently construct diverse types of nanovaccines and induce potent immune responses. To that end, it is critical for obtaining a potent self-adjuvant platform to assemble with different types of antigens into nanovaccines.

Results

In this study, we identified a new natural polysaccharide from the rhizomes of Bletilla striata (PRBS), and used this polysaccharide as a platform to construct diverse types of nanovaccines with potent self-adjuvant property. In the construction process of SARS-CoV-2 nanovaccine, PRBS molecules and RBD protein antigens were assembled into ~ 300 nm nanoparticles by hydrogen bond. For HIV nanovaccine, hydrophobic effect dominantly drove the co-assembly between PRBS molecules and Env expression plasmid into ~ 350 nm nanospheres. Importantly, PRBS can potently activate the behaviors and functions of multiple immune cells such as macrophages, B cells and dendritic cells. Depending on PRBS-mediated immune activation, these self-adjuvant nanovaccines can elicit significantly stronger antigen-specific antibody and cellular responses in vivo, in comparison with their corresponding traditional vaccine forms. Moreover, we also revealed the construction models of PRBS-based nanovaccines by analyzing multiple assembly parameters such as bond energy, bond length and interaction sites.

Conclusions

PRBS, a newly-identified natural polysaccharide which can co-assemble with different types of antigens and activate multiple critical immune cells, has presented a great potential as a versatile platform to develop potent self-adjuvant nanovaccines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01533-3.

Physicochemical and antioxidant properties of Lycium barbarum seed dreg polysaccharides prepared by continuous extraction

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Lycium barbarum polysaccharides were continuously prepared using four different solvents..

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The monosaccharides analysis revealed xylose as the main sugar.

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Molecular weights of four LBSDPs were reported as 5985, 7062, 5962, and 8762 Da, respectively.

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HBSS and CASS had better solubility and oil holding capacity.

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CASS and CHSS showed foam capacity and foam stability.

Lycium barbarum seed dreg polysaccharides (LBSDPs) were continuously extracted with four different solvents [hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS), and concentrated alkaline (CASS)]. The present study characterized the physicochemical and anti-oxidant based functional properties of different LBSDPs. The monosaccharide analysis revealed xylose (64.63%, 70.00%, 44.71%, and 66.67%) as the main sugar with the molecular weights of 5985, 7062, 5962, and 8762 Da in HBSS, CHSS, DASS, and CASS, respectively. Among the four polysaccharides, CASS had the strongest DPPH radical scavenging ability and reducing power; while, CHSS had the strongest ferrous ions chelating ability and HBSS showed the strongest OH radical scavenging ability. In terms of functional properties, HBSS and CASS had better solubility and oil holding capacity, while, CASS and CHSS had higher foam capacity and foam stability. Altogether, the polysaccharides extracted from L. barbarum seed dreg exhibit a potential application prospect in functional food and cosmetics industries.

Synthesis, Characterization, and Bioactivities of Polysaccharide Metal Complexes: A Review

Natural polysaccharides are critical to a wide range of fields (e.g., medicine, food production, and cosmetics) for their various remarkable physical properties and biological activities. However, the bioactivities of naturally acquired polysaccharides may be unsatisfactory and limit their further applications. It is generally known that the chemical structure exhibited by polysaccharides lays the material basis for their biological activities. Accordingly, possible structural modifications should be conducted on polysaccharides for their enhancement. Recently, polysaccharides complexed with metal ions (e.g., Fe, Zn, Mg, Cr, and Pt) have been reported to be possibly used to improve their bioactivities. Moreover, since the properties exhibited by metal ions are normally conserved, polysaccharides may be endowed with new applications. In this review, the synthesis methods, characterization methods, and bioactivities of polysaccharide metal complexes are summarized specifically. Then, the application prospects and limitations of these complexes are analyzed and discussed.

A review on plant polysaccharide based on drug delivery system for construction and application, with emphasis on traditional Chinese medicine polysaccharide

Carbohydrate polymers with unique chemical composition, molecular weight and functional chemical groups show multiple potentials in drug delivery. Most carbohydrate polymers such as plant polysaccharides exhibit advantages of biodegradability, ease of modification, low immunogenicity and low toxicity. They can be conjugated, cross-linked or functionally modified, and then used as nanocarrier materials. Polysaccharide drug delivery system can avoid the phagocytosis of the reticuloendothelial system, prevent the degradation of biomolecules, and increase the bioavailability of small molecules, thus exerting effective therapeutic effects. Therefore, they have been fully explored. In this paper, we reviewed the construction methods of drug delivery systems based on carbohydrate polymers (astragalus polysaccharide, angelica polysaccharide, lycium barbarum polysaccharide, ganoderma lucidum polysaccharide, bletilla polysaccharide, glycyrrhiza polysaccharide, and epimedium polysaccharides, etc). The application of polysaccharide drug delivery systems to deliver small molecule chemotherapeutic drugs, gene drugs, and metal ion drugs was also briefly introduced. At the same time, the role of the polysaccharide drug delivery system in tumor treatment, targeted therapy, and wound healing was discussed. In addition, the research of polysaccharide delivery systems based on the therapeutic efficacy of traditional Chinese medicine was also summarized and prospected.

A review on the applications of Traditional Chinese medicine polysaccharides in drug delivery systems

Traditional Chinese medicine polysaccharides (TCMPs) are plentiful and renewable resources with properties such as biocompatibility, hydrophilicity, biodegradability, and low cytotoxicity. Because the polysaccharide molecular chain contains a variety of active groups, different polysaccharide derivatives can be easily produced through chemical modification. They have been increasingly used in drug delivery systems (DDS). However, the potential of polysaccharides is usually ignored due to their structural complexity, poor stability or ambiguity of mechanisms of actions. This review summarized the applications of TCMPs in DDS around four main aspects. The general characteristics of TCMPs as drug delivery carriers, as well as the relationships between structure and function of them were summarized. Meanwhile, the direction of preparing multifunctional drug delivery materials with synergistic effect by using TCMPs was discussed. This review aims to become a reference for further research of TCMPs and their derivatives, especially applications of them as carriers in pharmaceutical preparation industry.

Optimal intervention time of ADSCs for hepatic ischemia-reperfusion combined with partial resection injury in rats

AIMS

Hepatic ischemia reperfusion injury (HIRI) is a complication of liver surgery and liver transplantation. Adipose-derived stem cells (ADSCs) can inhibit oxidative stress and inflammation through a paracrine effect. This study aimed to determine the optimal time window of ADSCs transplantation to restore liver function after HIRI.

MAIN METHODS

A rat model of hepatic ischemia reperfusion combined with partial hepatectomy (HIR/PH) was established. The animals were injected intravenously with 2 × 10⁶ rat ADSCs 2 h before, immediately after, or 6 h after surgery. Liver tissues and blood samples were collected for routine histological and biochemical assays. The molecular changes were analyzed by qRT-PCR and western blotting.

KEY FINDINGS

ADSCs significantly improved liver tissue structure and decreased the levels of AST, ALT and ALP, which was indicative of functional recovery. In addition, transplantation of ADSCs immediately after operation decreased the levels of inflammation-related cytokines such as TNF-α, IL-1β and IL-6, and significantly increased the activity of antioxidant enzymes. At the same time, the expression of MDA was decreased. Mechanistically, ADSCs activated the Keap1/Nrf2 pathway in the injured liver. Transplantation of ADSCs pre- and 6 h post-operation did not significantly affect some indices such as mRNA and protein expression of HO-1, and protein expression of NQO1.

SIGNIFICANCE

Transplanting ADSCs immediately after surgery accelerated tissue repair and functional recovery of the liver by activating the Keap1/Nrf2 pathway, which inhibited hepatic inflammation and oxidative stress, and restored the hepatic microenvironment.

Lycium barbarum polysaccharides attenuate cardiovascular oxidative stress injury by enhancing the Keap1/Nrf2 signaling pathway in exhaustive exercise rats

Moderate exercise is beneficial to physical and mental health. When the amount of exercise and exercise intensity exceeds a certain limit and reaches the state of exhaustion, oxidative stress levels in the body increase, which can lead to oxidative stress‑associated damage. Lycium barbarum polysaccharide (LBP) is one of the primary active ingredients extracted from wolfberry. Following exhausting exercise in rats, LBP supplements decrease damage to the myocardium and blood vessels, indicating that LBP exerts a protective effect on the cardiovascular system. The Kelch‑like ECH‑associated protein 1 (Keap1)/NF‑E2‑related factor 2 (Nrf2) anti‑oxidative stress signaling pathway improves total oxidizing ability; anti‑apoptosis and other aspects serve a vital role. In the present study, LBP intervention was performed in vivo and in vitro to observe its effect on the Keap1/Nrf2 pathway and oxidative stress‑associated indicators in order to clarify its protective mechanism. For the in vivo experiments, 60 male Sprague‑Dawley rats were randomly divided into normal control and aerobic, exhaustive and exhaustive exercise + LBP (200 mg/kg/day) groups. For the in vitro experiments, a rat thoracic aortic endothelial cell (RTAEC) oxidative stress model was established using angiotensin II (AngII) and divided into blank control, LBP (3,200 µg/ml), AngII (1x10^‑4 mol/l) and AngII + LBP groups. For in vitro experiments, small interfering (si)RNA (50 nmol) was used to transfect RTAEC and induce gene silencing of Nrf2. ELISA, hematoxylin and eosin staining, TUNEL, immunofluorescence, western blotting, immunohistochemistry and reverse transcription‑quantitative PCR were used to evaluate and verify the effect of LBP on oxidative stress indicators and the expression of Keap1/Nrf2 antioxidative stress signaling pathway. The in vivo experiments showed that LBP decreased the expression of serum malondialdehyde (MDA) and AngII, as well as apoptosis of blood vessels and cardiomyocytes and expression of TNF‑α in rats following exhaustive exercise. Meanwhile, LBP enhanced expression of the Keap1/Nrf2 signaling pathway and downstream associated protein glutamyl‑cysteine synthetase catalytic subunit (GCLC), quinone oxidoreductase 1 (NQO1) and glutamate‑cysteine ligase modified subunit (GCLM) in the thoracic aorta and myocardium of rats following exhaustive exercise. In RTAEC in vitro, LBP decreased the expression of MDA and TNF‑α in the supernatant, promoted the nuclear translocation of Nrf2 and increased expression levels of GCLC, NQO1 and GCLM. Following siNrf2 transfection into endothelial cells, the anti‑inflammatory and antioxidant stress effects of LBP were decreased. LBP was found to enhance the expression of the Keap1/Nrf2 antioxidant stress signaling pathway in endothelial cells, decreasing oxidative stress and the inflammatory response. Moreover, LBP improved the antioxidant stress ability of endothelial cells and alleviated injury of myocardial vascular tissue, thereby protecting the cardiovascular system.

Synthesis, stability and anti-fatigue activity of selenium nanoparticles stabilized by Lycium barbarum polysaccharides

Lycium barbarum polysaccharides (LBP) with different molecular weights (LBP1, LBP2 and LBP3) of 92,441 Da, 7714 Da, and 3188 Da were used as stabilizers and capping agents to prepare uniformly dispersed selenium nanoparticles (SeNPs), and determined the storage stability. In addition, the anti-fatigue activity of LBP-decorated SeNPs with the best stability (LBP1-SeNPs) was estimated by using forced swimming test. The results showed that LBP1-SeNPs exhibited smaller particle size and more excellent stability than those of LBP2-SeNPs and LBP3-SeNPs when the storage time was extended to 30 days, and the average particle size was maintained at about 105.4 nm. The exhaustion swimming time of all tested dose groups of LBP1-SeNPs was significantly longer than the control group (p < 0.05), and the high-dose group among them was even obviously longer than the positive group (p < 0.05). The results of glycogen, blood urea nitrogen (BUN), blood lactic acid (BLA), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were further confirmed that LBP1-SeNPs could relieve fatigue by increasing the reserve of glycogen, enhancing antioxidant enzyme levels and regulating metabolic mechanism. These results demonstrated that LBP1-SeNPs could be developed as a potential anti-fatigue nutritional supplement.

Platinum (II)-coordinated Portulaca oleracea polysaccharides as metal-drug based polymers for anticancer study

Novel polysaccharide-platinum conjugated polymers bearing alendronate on Portulaca oleracea polysaccharides (PPS) were designed and synthesized. Their chemical structures and properties were characterized by Fourier transform infrared spectroscopy (FT-IR), ¹H NMR and ³¹P NMR spectroscopy, Thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), UV-vis spectrophotometer (UV-vis) and other analysis methods. The results demonstrated that alendronate can be used as the linker of Portulaca oleracea polysaccharides and platinum compounds. Portulaca oleracea polysaccharides-alendronate (PPS-ALN) conjugates exhibited stronger antioxidant ability than PPS. The cytotoxicity assay to cancer cells was tested in vitro, and the Portulaca oleracea polysaccharides-alendronate-platinum (PPS-ALN-Pt) conjugates strongly inhibited the proliferation of cancer cells than PPS and PPS-ALN. The evaluation of complexes affinity toward supercoiled plasmid DNA, displayed a high DNA interaction. Interestingly, the platinum conjugates displayed immunological competence in HeLa cells by cellular immunofluorescence assay. Besides, the cellular platinum accumulation of PPS-ALN-Pt conjugates was higher than that of cisplatin in HeLa cells, implying that the polysaccharide-platinum conjugated polymers might have a synergistically therapeutic application in metal anticancer drug delivery.

Synthesis and biological evaluation of biotin-conjugated Portulaca oleracea polysaccharides

Biotinylated Portulaca oleracea polysaccharide (Bio-POP) conjugates were successfully prepared by the esterification reaction. The biotinylated polysaccharide products were an off-white powder with an average degree of substitution of 42.5%. After grafting biotin onto POP, the thermal stability of Bio-POP conjugates was much higher than that of POP and the surface topography of Bio-POP was a loose and porous cross-linked structure. The cytotoxicity assay in vitro demonstrated that POP, biotin, and Bio-POP conjugates exhibited different cytotoxicity to HeLa, MCF-7, LO-2, and A549, in particular POP inhibited the growth of the A549 cell line more than other cell lines. The nuclear staining method demonstrated that Bio-POP conjugates can interfere with the apoptosis of A549 cells to some extent and the immunofluorescence staining photograph illustrated that Bio-POP conjugates induced A549 cells to exhibit immune activity. Therefore, the combination of biotin and Portulaca oleracea polysaccharides had immune synergistic therapeutic effects on A549 cells and can be applied in the field of anti-tumor conjugate drugs.

Biotin grafted onto Portulaca oleracea polysaccharides (Bio-POP) was successfully prepared by the esterification reaction. Bio-POP conjugates had an obvious effect on the proliferation of A549 cells and induced A549 cells to exhibit immune activity.

Probiotic fermentation modifies the structures of pectic polysaccharides from carrot pulp

Previous studies have suggested that water-soluble polysaccharides from fermented carrot pulp (WSP-p) have stronger anti-diabetic effects than those from un-fermented carrot pulp (WSP-n). This study aimed to improve understanding of these functional differences by comparing their molecular structures. Weight-average molecular weights of WSP-p fractions were lower than those of the corresponding WSP-n fractions. While both WSPs had similar functional groups, more fragmented particles were observed on the surface of large particles of WSP-n than WSP-p. Monosaccharide composition and methylation analysis confirmed that both WSP-p and WSP-n were pectic polysaccharides, containing rhamnogalacturonan-I-type polysaccharides with 1,4-linked α-d-galacturonic acid residues and homogalacturonan regions with 1,4-GalpA linkages. ¹H and ¹³C NMR showed that they had similar linkage patterns. These findings suggested that probiotic fermentation of WSP mainly cleaved the linkages between repeating units, and resulted in less polydisperse molecular size distributions.