{"results":[{"id":"ss_36ca7c62f99e5061b17df029fcc5ca56d07200a1","title":"Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy","authors":[{"name":"Wenchao Sheng"},{"name":"Z. Zhuang"},{"name":"Minrui Gao"},{"name":"Jie Zheng"},{"name":"Jingguang G. Chen"},{"name":"Yushan Yan"}],"abstract":"The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum. Hydrogen oxidation and evolution are two of the key reactions in renewable energy conversion and storage devices. Here, the authors report the correlation between reaction rate and measured hydrogen binding energy for polycrystalline platinum in buffer solutions ranging from pH 0 to 13.","source":"Semantic Scholar","year":2015,"language":"en","subjects":["Chemistry","Medicine"],"doi":"10.1038/ncomms6848","url":"https://www.semanticscholar.org/paper/36ca7c62f99e5061b17df029fcc5ca56d07200a1","pdf_url":"https://www.nature.com/articles/ncomms6848.pdf","is_open_access":true,"citations":891,"published_at":"","score":85.73},{"id":"ss_4555d241f7f7a5b7b73ed100f7cfb70bc7d58105","title":"Preparation and application of pH-responsive drug delivery systems.","authors":[{"name":"Haitao Ding"},{"name":"Ping Tan"},{"name":"Shiqin Fu"},{"name":"Xiaohe Tian"},{"name":"Hu Zhang"},{"name":"Xuelei Ma"},{"name":"Zhongwei Gu"},{"name":"Kui Luo"}],"abstract":"Microenvironment-responsive drug delivery systems (DDSs) can achieve targeted drug delivery, reduce drug side effects and improve drug efficacies. Among them, pH-responsive DDSs have gained popularity since the pH in the diseased tissues such as cancer, bacterial infection and inflammation differs from a physiological pH of 7.4 and this difference could be harnessed for DDSs to release encapsulated drugs specifically to these diseased tissues. A variety of synthetic approaches have been developed to prepare pH-sensitive DDSs, including introduction of a variety of pH-sensitive chemical bonds or protonated/deprotonated chemical groups. A myriad of nano DDSs have been explored to be pH-responsive, including liposomes, micelles, hydrogels, dendritic macromolecules and organic-inorganic hybrid nanoparticles, and micron level microspheres. The prodrugs from drug-loaded pH-sensitive nano DDSs have been applied in research on anticancer therapy and diagnosis of cancer, inflammation, antibacterial infection, and neurological diseases. We have systematically summarized synthesis strategies of pH-stimulating DDSs, illustrated commonly used and recently developed nanocarriers for these DDSs and covered their potential in different biomedical applications, which may spark new ideas for the development and application of pH-sensitive nano DDSs.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.1016/j.jconrel.2022.05.056","url":"https://www.semanticscholar.org/paper/4555d241f7f7a5b7b73ed100f7cfb70bc7d58105","is_open_access":true,"citations":452,"published_at":"","score":79.56},{"id":"ss_99ffe46b16c63113d67a02543430cb78a5055675","title":"Preparation of an intelligent pH film based on biodegradable polymers and roselle anthocyanins for monitoring pork freshness.","authors":[{"name":"Junjun Zhang"},{"name":"Xiaobo Zou"},{"name":"Xiaodong Zhai"},{"name":"Xiaowei Huang"},{"name":"Caiping Jiang"},{"name":"M. Holmes"}],"abstract":"This study aims to develop an intelligent indicating film based on biodegradable polymers incorporated with roselle anthocyanins to monitor pork freshness. Three different films were prepared by using two substances of starch, polyvinyl alcohol and chitosan. The UV-vis spectra and color of anthocyanins changed at pH 2-12. SEM photographs showed that the compatibility of films was improved with the addition of anthocyanins. Furthermore, the polyvinyl alcohol/chitosan/roselle anthocyanins film had the highest tensile strength (98.28 MPa). The starch/polyvinyl alcohol/roselle anthocyanins film had the highest antioxidant activity (524.07%) and the best color stability. The starch/polyvinyl alcohol/roselle anthocyanins film showed visible changes from red to green when employed to monitor the freshness of pork stored at 25 °C, before the TVB-N value of the pork gradually increased to the rejection limit (15 mg/100 g) at 36 h. Therefore, the indicator film can be used to monitor pork freshness for intelligent packaging.","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Chemistry","Medicine"],"doi":"10.1016/j.foodchem.2018.08.041","url":"https://www.semanticscholar.org/paper/99ffe46b16c63113d67a02543430cb78a5055675","pdf_url":"https://www.sciencedirect.com/science/article/am/pii/S0308814618314420","is_open_access":true,"citations":547,"published_at":"","score":79.41},{"id":"ss_08c594eeb99c00d3a612d8d31710819e1d2d33bb","title":"pH effects on the electrochemical reduction of CO(2) towards C2 products on stepped copper","authors":[{"name":"Xinyan Liu"},{"name":"P. Schlexer"},{"name":"Jianping Xiao"},{"name":"Yongfei Ji"},{"name":"Lei Wang"},{"name":"Robert B. Sandberg"},{"name":"Michael T. Tang"},{"name":"Kristopher S. Brown"},{"name":"Hongjie Peng"},{"name":"Stefan Ringe"},{"name":"C. Hahn"},{"name":"T. Jaramillo"},{"name":"J. Nørskov"},{"name":"Karen Chan"}],"abstract":"We present a microkinetic model for CO(2) reduction (CO(2)R) on Cu(211) towards C2 products, based on energetics estimated from an explicit solvent model. We show that the differences in both Tafel slopes and pH dependence for C1 vs C2 activity arise from differences in their multi-step mechanisms. We find the depletion in C2 products observed at high overpotential and high pH to arise from the 2nd order dependence of C-C coupling on CO coverage, which decreases due to competition from the C1 pathway. We further demonstrate that CO(2) reduction at a fixed pH yield similar activities, due to the facile kinetics for CO2 reduction to CO on Cu, which suggests C2 products to be favored for CO2R under alkaline conditions. The mechanistic insights of this work elucidate how reaction conditions can lead to significant enhancements in selectivity and activity towards higher value C2 products. CO2 conversion to reduced products provides a use for greenhouse gases, but reaction complexity stymies mechanistic studies. Here, authors present a microkinetic model for CO2 and CO reduction on copper, based on ab initio simulations, to elucidate pH’s impact on competitive reaction pathways.","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Medicine","Chemistry"],"doi":"10.1038/s41467-018-07970-9","url":"https://www.semanticscholar.org/paper/08c594eeb99c00d3a612d8d31710819e1d2d33bb","pdf_url":"https://www.nature.com/articles/s41467-018-07970-9.pdf","is_open_access":true,"citations":479,"published_at":"","score":77.37},{"id":"ss_f042b50222e901dec8190d8d90c7619dfd3986ed","title":"The soil pH and heavy metals revealed their impact on soil microbial community.","authors":[{"name":"Misbah Naz"},{"name":"Z. Dai"},{"name":"Sajid T. Hussain"},{"name":"M. Tariq"},{"name":"Subhan Danish"},{"name":"I. Khan"},{"name":"S. Qi"},{"name":"D. Du"}],"abstract":"Soil microbial community is the main indicator having a crucial role in the remediation of polluted soils. These microbes can alter soil pH, organic matter in soils (SOM), soil physic-chemical properties, and potential soil respiration rate via their enzymatic activities. Similarly, heavy metals also have a crucial role in soil enzymatic activities. For this purpose, a number of methods are studied to evaluate the impact of soil pH (a key factor in the formation of biogeographic microbial patterns in bacteria) on bacterial diversity. The effects of pH on microbial activity are glamorous but still unclear. Whereas, some studies also indicate that soil pH alone is not the single key player in the diversity of soil bacteria. Ecological stability is achieved in a pollution-free environment and pH value. The pH factor has a significant impact on the dynamics of microbes' communities. Here, we try to discuss factors that directly or indirectly affect soil pH and the impact of pH on microbial activity. It is also discussed the environmental factors that contribute to establishing a specific bacterial community structure that must be determined. From this, it can be concluded that the environmental impact on soil pH, reducing soil pH and interaction with this factor, and reducing the effect of soil pH on soil microbial community.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.1016/j.jenvman.2022.115770","url":"https://www.semanticscholar.org/paper/f042b50222e901dec8190d8d90c7619dfd3986ed","is_open_access":true,"citations":376,"published_at":"","score":77.28},{"id":"ss_4f085f059441bba04ff15a25b0b4194d69740b3a","title":"A Wearable Electrochemical Platform for Noninvasive Simultaneous Monitoring of Ca(2+) and pH.","authors":[{"name":"H. Nyein"},{"name":"W. Gao"},{"name":"Ziba Shahpar"},{"name":"S. Emaminejad"},{"name":"Samyuktha Challa"},{"name":"Kevin Chen"},{"name":"H. Fahad"},{"name":"Li-Chia Tai"},{"name":"H. Ota"},{"name":"Ronald W. Davis"},{"name":"A. Javey"}],"abstract":"","source":"Semantic Scholar","year":2016,"language":"en","subjects":["Materials Science","Medicine"],"doi":"10.1021/acsnano.6b04005","url":"https://www.semanticscholar.org/paper/4f085f059441bba04ff15a25b0b4194d69740b3a","pdf_url":"https://escholarship.org/content/qt688015nm/qt688015nm.pdf","is_open_access":true,"citations":570,"published_at":"","score":77.1},{"id":"ss_63a02fab59c74c3cf757c0f46332f42e52f3db6f","title":"pH-responsive self-healing injectable hydrogel based on N-carboxyethyl chitosan for hepatocellular carcinoma therapy.","authors":[{"name":"Jin Qu"},{"name":"Xin Zhao"},{"name":"P. Ma"},{"name":"Baolin Guo"}],"abstract":"","source":"Semantic Scholar","year":2017,"language":"en","subjects":["Materials Science","Medicine"],"doi":"10.1016/j.actbio.2017.06.001","url":"https://www.semanticscholar.org/paper/63a02fab59c74c3cf757c0f46332f42e52f3db6f","is_open_access":true,"citations":505,"published_at":"","score":76.15},{"id":"ss_f91120836a1f3187459d4280d9d62d15f6e7956b","title":"The effects of pH on nutrient availability depend on both soils and plants","authors":[{"name":"N. Barrow"},{"name":"A. Hartemink"}],"abstract":"The effects of pH on nutrient availability are not solely caused by to the effects on reaction with soils but are an interaction between these effects and the effects on rate of uptake by plants. Some effects are specific to particular ions, but an important aspect is that plant roots and soil particles both have variable charge surfaces. This influences availability, but in opposite directions. Sulfate is an example of this interplay. Its sorption by soil decreases markedly with increasing pH and thus “soil availability” increases. However, plant uptake also decreases with increasing pH thus “plant availability” decreases. For phosphate, the plant effect is stronger than the soil effect and uptake decreases with increasing pH. In contrast, effects of increasing pH on molybdate adsorption are so large that they dominate the overall effect. Sorption of cations, such as zinc or copper, increases with increasing pH but uptake rate also increases. The net effect is a small decrease in availability with increasing pH. Boron is an exception; there are small effects of pH on sorption; and it is the uncharged boric acid molecules that are taken up by plant roots. Their uptake is not affected by charge and uptake is proportional to the concentration of uncharged boric acid molecules. We argue that emphasis on the effects of pH on reactions with soil has led to a distorted picture of the effects of pH on nutrient availability.","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.1007/s11104-023-05960-5","url":"https://www.semanticscholar.org/paper/f91120836a1f3187459d4280d9d62d15f6e7956b","pdf_url":"https://link.springer.com/content/pdf/10.1007/s11104-023-05960-5.pdf","is_open_access":true,"citations":298,"published_at":"","score":75.94},{"id":"ss_9efca4314b89dffb8e45105e8b9ab638db5562cb","title":"A Multifunctional Pro‐Healing Zwitterionic Hydrogel for Simultaneous Optical Monitoring of pH and Glucose in Diabetic Wound Treatment","authors":[{"name":"Yingnan Zhu"},{"name":"Jiamin Zhang"},{"name":"Jiayin Song"},{"name":"Jing Yang"},{"name":"Zhengang Du"},{"name":"Weiqiang Zhao"},{"name":"Hongshuang Guo"},{"name":"Chiyu Wen"},{"name":"Qingsi Li"},{"name":"Xiaojie Sui"},{"name":"Lei Zhang"}],"abstract":"Diabetic ulcer is the most common kind of chronic wound worldwide. Though great efforts have been devoted, diabetic ulcer still remains as a challenge that requires constant monitoring and management. In this work, a multifunctional zwitterionic hydrogel is developed to simultaneously detect two fluctuant wound parameters, pH and glucose level, to monitor the diabetic wound status. A pH indicator dye (phenol red) and two glucose sensing enzymes, glucose oxidase (GOx) and horseradish peroxidase (HRP), are encapsulated in the anti‐biofouling and biocompatible zwitterionic poly‐carboxybetaine (PCB) hydrogel matrix. The visible images are collected by a smartphone and transformed into RGB signals to quantify the wound parameters. Results show that the activity and stability of both two enzymes are improved within PCB hydrogel, and the Kcat/Km value of PCB‐HRP is ≈5.5 fold of free HRP in artificial wound exudate. This novel wound dressing can successfully monitor the pH range of 4–8 and glucose level of 0.1–10 × 10−3 m. Meanwhile, it also provides a moist healing environment that can promote diabetic wound healing. This multifunctional wound dressing may open vistas in chronic wound management and guide the diabetes treatment in clinical applications.","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Materials Science"],"doi":"10.1002/adfm.201905493","url":"https://www.semanticscholar.org/paper/9efca4314b89dffb8e45105e8b9ab638db5562cb","is_open_access":true,"citations":431,"published_at":"","score":75.93},{"id":"ss_2e5a9ab9ebfa7203251a94ccc0de0aa3e476895a","title":"Soil organic matter priming: The pH effects","authors":[{"name":"Chaoqun Wang"},{"name":"Y. Kuzyakov"}],"abstract":"Priming of soil organic matter (SOM) decomposition by microorganisms is a key phenomenon of global carbon (C) cycling. Soil pH is a main factor defining priming effects (PEs) because it (i) controls microbial community composition and activities, including enzyme activities, (ii) defines SOM stabilization and destabilization mechanisms, and (iii) regulates intensities of many biogeochemical processes. In this critical review, we focus on prerequisites and mechanisms of PE depending on pH and assess the global change consequences for PE. The highest PEs were common in soils with pH between 5.5 and 7.5, whereas low molecular weight organic compounds triggered PE mainly in slightly acidic soils. Positive PEs up to 20 times of SOM decomposition before C input were common at pH around 6.5. Negative PEs were common at soil pH below 4.5 or above 7 reflecting a suboptimal environment for microorganisms and specific SOM stabilization mechanisms at low and high pH. Short‐term soil acidification (in rhizosphere, after fertilizer application) affects PE by: mineral‐SOM complexation, SOM oxidation by iron reduction, enzymatic depolymerization, and pH‐dependent changes in nutrient availability. Biological processes of microbial metabolism shift over the short‐term, whereas long‐term microbial community adaptations to slow acidification are common. The nitrogen fertilization induced soil acidification and land use intensification strongly decrease pH and thus boost the PE. Concluding, soil pH is one of the strongest but up to now disregarded factors of PE, defining SOM decomposition through short‐term metabolic adaptation of microbial groups and long‐term shift of microbial communities.","source":"Semantic Scholar","year":2024,"language":"en","subjects":["Medicine"],"doi":"10.1111/gcb.17349","url":"https://www.semanticscholar.org/paper/2e5a9ab9ebfa7203251a94ccc0de0aa3e476895a","is_open_access":true,"citations":237,"published_at":"","score":75.11},{"id":"ss_cb3c05071ac5f84e51b236e98908cda0c3d521c6","title":"Modifying the physicochemical properties of pea protein by pH-shifting and ultrasound combined treatments.","authors":[{"name":"Shanshan Jiang"},{"name":"Junzhou Ding"},{"name":"J. Andrade"},{"name":"T. Rababah"},{"name":"A. Almajwal"},{"name":"M. Abulmeaty"},{"name":"H. Feng"}],"abstract":"","source":"Semantic Scholar","year":2017,"language":"en","subjects":["Chemistry","Medicine"],"doi":"10.1016/j.ultsonch.2017.03.046","url":"https://www.semanticscholar.org/paper/cb3c05071ac5f84e51b236e98908cda0c3d521c6","is_open_access":true,"citations":457,"published_at":"","score":74.71000000000001},{"id":"ss_51a39e2e59c49b8dbf03d02a00f1594f2806770f","title":"pH‐responsive polymers for drug delivery: Trends and opportunities","authors":[{"name":"J. Singh"},{"name":"P. Nayak"}],"abstract":"Polymer science has applications in biomedical engineering, prosthetics, surgical implants, and prospective pharmaceutical excipients for drug delivery. “Intelligent or Smart Polymers” are created for drug targeting either by derivatization of natural polymers or controlled radical polymerization of electrolytes. Their mode of action is governed by the environmental stimuli viz. temperature, pH, ionic concentration, magnetism, and so on. pH‐responsive polymers, because of their self‐assembling behavior, alter their solubility, conformation, surface activity, and hydrophilicity when exposed to a specific pH. The physiological pH varies from acidic nuclei to alkaline cytoplasm and highly acidic gastric juice to slightly alkaline plasma; thus, various polymers are under study for delivering small molecules, genes, peptides, enzymes, growth factors, and antibodies. The non‐invasive drug delivery routes like oral, ocular, nasal, pulmonary, transdermal, and rectal routes can be explored for targeting recombinant proteins, monoclonal antibodies, and small molecules with particular emphasis on the individual's physiological and pathological state. Further, these polymers can be designed into various architectures like dendrimers, liposomes, micelles, and metallic nanoparticles that can serve as drug reservoirs for sustaining drug release. The challenges in this field are the selection of biocompatible polymers with ease of synthesis and scale‐up, ensuring effective drug‐loading, and stability aspects, producing robust pharmacological data, and timely regulatory approvals. This review exclusively explores the physicochemical characteristics of pH‐responsive polymers, their categorization, various architectural entities, recent studies and patents, and their emerging applications concerning specific diseases.","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.1002/pol.20230403","url":"https://www.semanticscholar.org/paper/51a39e2e59c49b8dbf03d02a00f1594f2806770f","pdf_url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/pol.20230403","is_open_access":true,"citations":197,"published_at":"","score":72.91},{"id":"ss_5610064871419211125b6621a50f708f69d28edc","title":"pH-Responsive Polymer Nanomaterials for Tumor Therapy","authors":[{"name":"Shunli Chu"},{"name":"Xiaolu Shi"},{"name":"Ye Tian"},{"name":"Fengxiang Gao"}],"abstract":"The complexity of the tumor microenvironment presents significant challenges to cancer therapy, while providing opportunities for targeted drug delivery. Using characteristic signals of the tumor microenvironment, various stimuli-responsive drug delivery systems can be constructed for targeted drug delivery to tumor sites. Among these, the pH is frequently utilized, owing to the pH of the tumor microenvironment being lower than that of blood and healthy tissues. pH-responsive polymer carriers can improve the efficiency of drug delivery in vivo, allow targeted drug delivery, and reduce adverse drug reactions, enabling multifunctional and personalized treatment. pH-responsive polymers have gained increasing interest due to their advantageous properties and potential for applicability in tumor therapy. In this review, recent advances in, and common applications of, pH-responsive polymer nanomaterials for drug delivery in cancer therapy are summarized, with a focus on the different types of pH-responsive polymers. Moreover, the challenges and future applications in this field are prospected.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.3389/fonc.2022.855019","url":"https://www.semanticscholar.org/paper/5610064871419211125b6621a50f708f69d28edc","pdf_url":"https://www.frontiersin.org/articles/10.3389/fonc.2022.855019/pdf","is_open_access":true,"citations":193,"published_at":"","score":71.78999999999999},{"id":"ss_d8050558e0df54154e34add72854af3443872789","title":"Soil pH - nutrient relationships: the diagram","authors":[{"name":"A. Hartemink"},{"name":"N. Barrow"}],"abstract":"","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.1007/s11104-022-05861-z","url":"https://www.semanticscholar.org/paper/d8050558e0df54154e34add72854af3443872789","is_open_access":true,"citations":153,"published_at":"","score":71.59},{"id":"ss_1f5b510446a8b7ec1d92099dece34871c8e530ec","title":"A Dual pH-Responsive Hydrogel Actuator for Lipophilic Drug Delivery.","authors":[{"name":"Zilong Han"},{"name":"Peng Wang"},{"name":"G. Mao"},{"name":"Tenghao Yin"},{"name":"Danming Zhong"},{"name":"Burebi Yiming"},{"name":"Xiaocheng Hu"},{"name":"Z. Jia"},{"name":"G. Nian"},{"name":"S. Qu"},{"name":"Wei Yang"}],"abstract":"As one of the most promising drug delivery carriers, hydrogels have received considerable attention in recent years. Many previous efforts focused on diffusion-controlled release which allows hydrogels to load and release drugs in vitro and/or in vivo. However, it hardly applies to lipophilic drug delivery due to their poor compatibility with hydrogels. Herein, we propose a novel method for lipophilic drug release based on a dual pH-responsive hydrogel actuator. Specifically, the drug is encapsulated and can be released by a dual pH-controlled capsule switch. Inspired by the deformation mechanism of Drosera leaves, we fabricate the capsule switch with a double-layer structure that is made of two kinds of pH-responsive hydrogel. Two layers are covalently bonded together through silane coupling agents. They can bend collaboratively in basic or acidic environment to achieve \"turn on\" motion of capsule switch. By incorporating an array of parallel elastomer-stripes on one side of the hydrogel bilayer, various motions (e.g., bending, twisting, and rolling) of the hydrogel bilayer actuator were achieved. We conducted in vitro lipophilic drug release test. The feasibility of this new drug release method is verified. We believe this dual pH-responsive actuator-controlled drug release method may enlighten the possibilities for various drug delivery systems.","source":"Semantic Scholar","year":2020,"language":"en","subjects":["Medicine","Materials Science"],"doi":"10.1021/acsami.9b21713","url":"https://www.semanticscholar.org/paper/1f5b510446a8b7ec1d92099dece34871c8e530ec","is_open_access":true,"citations":243,"published_at":"","score":71.28999999999999},{"id":"ss_9241573ddcb525b6decc759f51cafbbafe0d7ac7","title":"pH-Responsive carriers for oral drug delivery: challenges and opportunities of current platforms","authors":[{"name":"Lin Liu"},{"name":"Wendong Yao"},{"name":"Yuefeng Rao"},{"name":"Xiaoyang Lu"},{"name":"Jianqing Gao"}],"abstract":"Abstract Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines. This review provides a wide perspective on current status of pH-responsive oral drug delivery systems prepared mainly with organic polymers or inorganic materials, including the strategies used to overcome GI barriers, the challenges in their development and future prospects, with focus on technology trends to improve the bioavailability of orally delivered drugs, the mechanisms of drug release from pH-responsive oral formulations, and their application for drug delivery, such as protein and peptide therapeutics, vaccination, inflammatory bowel disease (IBD) and bacterial infections.","source":"Semantic Scholar","year":2017,"language":"en","subjects":["Medicine"],"doi":"10.1080/10717544.2017.1279238","url":"https://www.semanticscholar.org/paper/9241573ddcb525b6decc759f51cafbbafe0d7ac7","pdf_url":"https://www.tandfonline.com/doi/pdf/10.1080/10717544.2017.1279238?needAccess=true","is_open_access":true,"citations":316,"published_at":"","score":70.48},{"id":"crossref_10.1002/macp.202400469","title":"Zwitterionic Polycatechols for Covalent Conjugation With Bortezomib and pH‐Triggered Release","authors":[{"name":"Naikuan Fu"},{"name":"Ao Li"},{"name":"Jing Zhang"},{"name":"Peng Zhang"},{"name":"Hong Zhang"},{"name":"Shicheng Yang"},{"name":"Jianhua Zhang"}],"abstract":"Abstract The therapeutic efficacy of Bortezomib (BTZ) is severely limited by its low solubility, poor stability in vivo and nonspecific toxicity. PEGylated nanocarriers can improve drug delivery efficiency, but their applications often suffer from low drug loading, premature leakage and accelerated blood clearance phenomenon. Herein a kind of catechol‐functionalized and sulfobetaine‐based zwitterionic block copolymer (PGMAD‐PSBMA) is prepared by RAFT copolymerization and an epoxy‐amino click reaction. And then PGMAD‐PSBMA is readily used to conjugate with BTZ by the formation of dynamic boronate bonds to obtain zwitterionic BTZ prodrug (PGMAD@BTZ‐PSBMA) and PGMAD@BTZ‐PSBMA micelles. The structure and morphology, physicochemical characteristics, drug loading, pH‐triggered drug release as well as in vitro cytotoxicity of PGMAD@BTZ‐PSBMA micelles are investigated in detail. The results demonstrate that PGMAD@BTZ‐PSBMA micelles can not only possess high drug loading (12.9%) and stable dispersion in physiological pH condition (pH 7.4), but also respond to the tumor acid microenvironment and achieve pH‐responsive BTZ release. The nanocarriers designed here readily combine the desirable functions of polycatechols for stable conjugation and acid‐triggered release and polysulfobetaines for long circulation in blood, which have great potential to enhance therapeutic efficacy and reduce toxic side effects of BTZ and other boronic acid‐containing drugs, such as Ixazomib and Steboronine.","source":"CrossRef","year":2025,"language":"en","subjects":null,"doi":"10.1002/macp.202400469","url":"https://doi.org/10.1002/macp.202400469","is_open_access":true,"citations":2,"published_at":"","score":69.06},{"id":"ss_eb727dd48ae7bcfe94caa5311b9ff781bdfbf513","title":"Role of pH Value in Clinically Relevant Diagnosis","authors":[{"name":"Shu-Hua Kuo"},{"name":"C. Shen"},{"name":"Ching-Fen Shen"},{"name":"Chao-Min Cheng"}],"abstract":"As a highly influential physiological factor, pH may be leveraged as a tool to diagnose physiological state. It may be especially suitable for diagnosing and assessing skin structure and wound status. Multiple innovative and elegant smart wound dressings combined with either pH sensors or drug control-released carriers have been extensively studied. Increasing our understanding of the role of pH value in clinically relevant diagnostics should assist clinicians and improve personal health management in the home. In this review, we summarized a number of articles and discussed the role of pH on the skin surface as well as the factors that influence skin pH and pH-relevant skin diseases, but also the relationship of skin pH to the wound healing process, including its influence on the activity of proteases, bacterial enterotoxin, and some antibacterial agents. A great number of papers discussing physiological pH value have been published in recent decades, far too many to be included in this review. Here, we have focused on the impact of pH on wounds and skin with an emphasis on clinically relevant diagnosis toward effective treatment. We have also summarized the differences in skin structure and wound care between adults and infants, noting that infants have fragile skin and poor skin barriers, which makes them more vulnerable to skin damage and compels particular care, especially for wounds.","source":"Semantic Scholar","year":2020,"language":"en","subjects":["Medicine"],"doi":"10.3390/diagnostics10020107","url":"https://www.semanticscholar.org/paper/eb727dd48ae7bcfe94caa5311b9ff781bdfbf513","pdf_url":"https://www.mdpi.com/2075-4418/10/2/107/pdf?version=1583045271","is_open_access":true,"citations":158,"published_at":"","score":68.74000000000001},{"id":"ss_7521fdd5521e8be04054b0e67c288fafe0db05a5","title":"Aerosol pH and its driving factors in Beijing","authors":[{"name":"Jing Ding"},{"name":"P. Zhao"},{"name":"Jie Su"},{"name":"Qun Dong"},{"name":"Xiang Du"},{"name":"Yufen Zhang"}],"abstract":"Abstract. Aerosol acidity plays a key role in secondary aerosol formation. The high-temporal-resolution PM2.5 pH and size-resolved aerosol pH in Beijing were calculated with ISORROPIA II. In 2016–2017, the mean PM2.5 pH (at relative humidity (RH) \u003e 30 %) over four seasons was 4.5±0.7 (winter) \u003e 4.4±1.2 (spring) \u003e 4.3±0.8 (autumn) \u003e 3.8±1.2 (summer), showing moderate acidity. In coarse-mode aerosols, Ca2+ played an important role in aerosol pH. Under heavily polluted conditions, more secondary ions accumulated in the coarse mode, leading to the acidity of the coarse-mode aerosols shifting from neutral to weakly acidic. Sensitivity tests also demonstrated the significant contribution of crustal ions to PM2.5 pH. In the North China Plain (NCP), the common driving factors affecting PM2.5 pH variation in all four seasons were SO42-, TNH3 (total ammonium (gas + aerosol)), and temperature, while unique factors were Ca2+ in spring and RH in summer. The decreasing SO42- and increasing NO3- mass fractions in PM2.5 as well as excessive NH3 in the atmosphere in the NCP in recent years are the reasons why aerosol acidity in China is lower than that in Europe and the United States. The nonlinear relationship between PM2.5 pH and TNH3 indicated that although NH3 in the NCP was abundant, the PM2.5 pH was still acidic because of the thermodynamic equilibrium between NH4+ and NH3. To reduce nitrate by controlling ammonia, the amount of ammonia must be greatly reduced below excessive quantities.","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Chemistry"],"doi":"10.5194/ACP-19-7939-2019","url":"https://www.semanticscholar.org/paper/7521fdd5521e8be04054b0e67c288fafe0db05a5","pdf_url":"https://acp.copernicus.org/articles/19/7939/2019/acp-19-7939-2019.pdf","is_open_access":true,"citations":187,"published_at":"","score":68.61},{"id":"ss_d306c6d82f0a0bf69c79461090852073302003b2","title":"Manipulating extracellular tumour pH: an effective target for cancer therapy","authors":[{"name":"Guanyu Hao"},{"name":"Z. Xu"},{"name":"Li Li"}],"abstract":"The pH in tumour cells and the tumour microenvironment has played important roles in cancer development and treatment. It was thought that both the extracellular and intracellular pH values in tumours are acidic and lower than in normal cells. However, recent progress in the measurement of pH in tumour tissue has disclosed that the intracellular pH (pHi) of cancer cells is neutral or even mildly alkaline compared to normal tissue cells. This review article has summarized the recent advancement in the measurement pHi and extracellular pH (pHe) in cancer cells, and the effect of pHi and pHe on proliferation, migration and biological functions of cancer cells. This paper has also elaborated recent treatment strategies to manipulate pHi and pHe for cancer treatment. Based on the recent progress in pHi and pHe manipulation in cancer treatment, we have proposed potential nanoparticle-based strategies to manipulate pHi and pHe to effectively treat cancer.","source":"Semantic Scholar","year":2018,"language":"en","subjects":["Medicine","Chemistry"],"doi":"10.1039/c8ra02095g","url":"https://www.semanticscholar.org/paper/d306c6d82f0a0bf69c79461090852073302003b2","pdf_url":"https://pubs.rsc.org/en/content/articlepdf/2018/ra/c8ra02095g","is_open_access":true,"citations":214,"published_at":"","score":68.42}],"total":5730335,"page":1,"page_size":20,"sources":["CrossRef","Semantic Scholar"],"query":"physics.ao-ph"}