Browsing by Subject "pH"

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  • Kylä-Puhju, Maria; Ruusunen, Marita; Puolanne, Eero (Elsevier, 2005)
    The activity of glycogen debranching enzyme (GDE) was studied in relation to pH value and temperature in porcine masseter and longissimus dorsi muscles. A glycogen limit dextrin was used as the substrate for GDE, and the enzyme was derived from raw meat extracts. In both muscles, the pH only weakly affected on activity of GDE at the pH values found in carcasses post-slaughter. However, the activity of GDE decreased strongly (P < 0.001) when the temperature decreased from values of 39 °C and 42 °C found just after slaughter to values of 4 °C and 15 °C found during cooling. In both muscles the activity of GDE began to fall at temperatures below 39 °C and was almost zero when the temperature decreased to below 15 °C. Thus, the activity of GDE may control the rate of glycogenolysis and glycolysis, but does not block rapid glycolysis and pH decrease when the temperature is high. This may be important in PSE meat, where the pH decreases rapidly at high temperatures, but rapid cooling could limit the activity of GDE and thus glycogenolysis. As expected, GDE was more active in the light longissimus dorsi muscle than in the dark masseter muscle.
  • Carlberg, J. J. (Suomen metsätieteellinen seura, 1935)
  • Remes, Lassi (Helsingin yliopisto, 2014)
    Growing medium and its properties are an important factor affecting plant growth. One can improve the properties of growing medium with different amendments such as lime, nutrients and wetting agents depending on the requirements of the plant. The objective of this study was to examine a soil amendment called BRT EverGreen powder and its effect on white sphagnum peat and on plant growth. The powder has been created by a Finnish company Biomass Refine Technologies BRT ltd Oy. The powder is synthetically made of ureaformaldehyderesin and phosphoric acid includes added water retention lowering surfactants. In cultivation the goal by using BRT powder is to improve water retention and wetting of the growing medium and increase plant available nutrients. This study consisted of three experiments with three different plants or plant mixtures: Lactuca sativa L. ‘Grand Rapids’, Ligularia × hessei and a mixture of lawn (Festuca rubra L., Poa pratensis L. and Agrostis capillaris L.). These plants were expected to benefit from improved water retention of the growing medium. During the experiments the effect of BRT powder on the properties of white sphagnum peat and the speed, amount and quality of plant growth was measured. All plants got the same amount of water by irrigation. Mild nutrient solution was given to Lactuca and Ligularia with irrigation water three times during the experiments and no fertilizers were applied to the grass. The water retention ability of white sphagnum peat was not improved in plantless short term experiments by adding BRT powder. However the results given by direct moisture measurements from the growing medium implied that the BRT powder increased slightly the moisture content of the medium compared to pure peat. From the three different plant types tested only grass grew faster with BRT though the quality wasn’t as good as in pure peat. The improvement in growth was probably due to nutrients in BRT powder because no nutrients were applied to the grass unlike to Lactuca and Ligularia. There were no differences in the growth or quality of Lactuca. Ligularia did not grow as well with powder as in pure peat. Adding lime decreased the negative effect of BRT powder so the very low pH of the powder presumably hampered growth of Ligularia. BRT powder affects the growth of different plants in different ways. This makes its use in cultivation difficult because one does not know what the effect will be. The use of BRT is not recommendable in container cultivation with Lactuca or Ligularia when using peat. BRT powder can increase the growth of grass if additional fertilization is not applied.
  • Jain, Monika; Yadav, Mithilesh; Kohout, Tomas; Lahtinen, Manu; Garg, Vinod Kumar; Sillanpää, Mika (2018)
    Iron oxide (Fe3O4) and iron oxide/activated carbon (Fe3O4/AC) were fabricated by co-precipitation method for the removal of Cr(VI), Cu(II) and Cd(II) ions from aqueous solution in batch mode. These nanoparticles were characterized by BET, FTIR, XRD, SEM/TEM and VSM. The optimum conditions for the removal of ions were pH = 2 for Cr(VI) and 6 for Cu(II) and Cd (II), initial metal ion concentration = 50 mg L-1, nanoparticle dose = 50 mg/10 mL, temperature = 25 +/- 1 degrees C, shaking speed = 180 rpm and contact time = 3 h. The equilibrium data of ions sorption were well described by Langmuir, Freundlich, Redlich-Peterson and Intraparticle Diffusion model. The R-2 values obtained by Langmuir model were highest by Fe3O4/AC for Cr(VI) = 0.9994, Cu(II) = 0.9998 and Cd(II) = 0.9750. The temperature dependent study in the range of 288-328 K confirmed that the adsorption process was endothermic in nature. Desorption studies with 0.1M HCl stated that these nanoparticles can be regenerated effectively and can be used after four adsorption-desorption cycles without any mass loss.
  • Lammel, Daniel R; Barth, Gabriel; Ovaskainen, Otso; Cruz, Leonardo M; Zanatta, Josileia A; Ryo, Masahiro; de Souza, Emanuel M; Pedrosa, Fábio O (BioMed Central, 2018)
    Abstract Background pH is frequently reported as the main driver for prokaryotic community structure in soils. However, pH changes are also linked to “spillover effects” on other chemical parameters (e.g., availability of Al, Fe, Mn, Zn, and Cu) and plant growth, but these indirect effects on the microbial communities are rarely investigated. Usually, pH also co-varies with some confounding factors, such as land use, soil management (e.g., tillage and chemical inputs), plant cover, and/or edapho-climatic conditions. So, a more comprehensive analysis of the direct and indirect effects of pH brings a better understanding of the mechanisms driving prokaryotic (archaeal and bacterial) community structures. Results We evaluated an agricultural soil pH gradient (from 4 to 6, the typical range for tropical farms), in a liming gradient with confounding factors minimized, investigating relationships between prokaryotic communities (16S rRNA) and physical–chemical parameters (indirect effects). Correlations, hierarchical modeling of species communities (HMSC), and random forest (RF) modeling indicated that both direct and indirect effects of the pH gradient affected the prokaryotic communities. Some OTUs were more affected by the pH changes (e.g., some Actinobacteria), while others were more affected by the indirect pH effects (e.g., some Proteobacteria). HMSC detected a phylogenetic signal related to the effects. Both HMSC and RF indicated that the main indirect effect was the pH changes on the availability of some elements (e.g., Al, Fe, and Cu), and secondarily, effects on plant growth and nutrient cycling also affected the OTUs. Additionally, we found that some of the OTUs that responded to pH also correlated with CO2, CH4, and N2O greenhouse gas fluxes. Conclusions Our results indicate that there are two distinct pH-related mechanisms driving prokaryotic community structures, the direct effect and “spillover effects” of pH (indirect effects). Moreover, the indirect effects are highly relevant for some OTUs and consequently for the community structure; therefore, it is a mechanism that should be further investigated in microbial ecology.
  • Lammel, Daniel R.; Barth, Gabriel; Ovaskainen, Otso; Cruz, Leonardo M.; Zanatta, Josileia A.; Ryo, Masahiro; de Souza, Emanuel M.; Pedrosa, Fabio O. (2018)
    Background: pH is frequently reported as the main driver for prokaryotic community structure in soils. However, pH changes are also linked to "spillover effects" on other chemical parameters (e.g., availability of Al, Fe, Mn, Zn, and Cu) and plant growth, but these indirect effects on the microbial communities are rarely investigated. Usually, pH also co-varies with some confounding factors, such as land use, soil management (e.g., tillage and chemical inputs), plant cover, and/or edapho-climatic conditions. So, a more comprehensive analysis of the direct and indirect effects of pH brings a better understanding of the mechanisms driving prokaryotic (archaeal and bacterial) community structures. Results: We evaluated an agricultural soil pH gradient (from 4 to 6, the typical range for tropical farms), in a liming gradient with confounding factors minimized, investigating relationships between prokaryotic communities (16S rRNA) and physical-chemical parameters (indirect effects). Correlations, hierarchical modeling of species communities (HMSC), and random forest (RF) modeling indicated that both direct and indirect effects of the pH gradient affected the prokaryotic communities. Some OTUs were more affected by the pH changes (e.g., some Actinobacteria), while others were more affected by the indirect pH effects (e.g., some Proteobacteria). HMSC detected a phylogenetic signal related to the effects. Both HMSC and RF indicated that the main indirect effect was the pH changes on the availability of some elements (e.g., Al, Fe, and Cu), and secondarily, effects on plant growth and nutrient cycling also affected the OTUs. Additionally, we found that some of the OTUs that responded to pH also correlated with CO2, CH4, and N2O greenhouse gas fluxes. Conclusions: Our results indicate that there are two distinct pH-related mechanisms driving prokaryotic community structures, the direct effect and "spillover effects" of pH (indirect effects). Moreover, the indirect effects are highly relevant for some OTUs and consequently for the community structure; therefore, it is a mechanism that should be further investigated in microbial ecology.
  • Wu, Qimeng (Helsingin yliopisto, 2015)
    The literature review deals with water distribution in meat, the structure of the myofibrillar matrix, and the aspects related to the water-protein interaction. Special focus was given to the large water accessible area of myosin S1 units, surface hydrophobicity of proteins and factors affecting the hydrophobicity. Also the possible mechanisms of water-holding in meat were briefly introduced. The aim of the thesis was to study the effect of different ions and pH values on the surface hydrophobicity of the myosin S1 units, adding knowledge to the understanding of the interaction between myosin S1 units and water. Myosin S1 units were prepared from porcine longissimus dorsi muscle 48 h postmortem. Obtained myosin S1 units were subjected to 0.2 M, 0.4 M and 0.6 M ionic strength of NaCl and KCl and to pH 5.0, 5.5, 6.0, 6.5 and 7.0. The surface hydrophobicity of myosin S1 units was measured by fluorescent molecular probe (cis-Parinaric acid) method. The method of purifying myosin S1 units from porcine longissimus dorsi muscle 48 h postmortem was established under the conditions of our laboratory. Surface hydrophobicity was found to increase with increasing ionic strength of both KCl and NaCl. Concerning the different ions studied, only at 0.6 M, significantly higher surface hydrophobicity of myosin S1 units was measured in KCl compared to NaCl. This phenomenon is in accordance with chaotropic effect of K+ and Cl- and kosmotropic effect of Na+. Regarding the effect of pH, within KCl samples, more hydrophobicity myosin S1 unit was detected towards to the more acidic direction pH values than pH 6.0. For NaCl samples, at pH 5.5 and 6.0, surface hydrophobicity was significantly higher than at pH 5.0, 6.5 and 7.0. Differences may have been induced by the changes in the net charges of protein, and further in protein conformation. Considering the property of the protein surface, more hydrophobic protein results in less water-protein interaction. However, to look at the whole scenario of the interaction between myosin S1 units and water, changes of net charges of myosin S1 units and water structure at vicinity of them should be further studied.
  • Kalmu, Niina (Helsingin yliopisto, 2021)
    Poultry meat has become popular in human diet and to secure the growing demand of poultry meat, breeders have developed broilers with fast growth and high breast muscle yield. Because of this genetic selection modern broilers are suffering from various quality defects in their breast muscles, one of which is called WB myopathy. The aim of the thesis was to study whether exercise, WB status or age have effects on ultimate pH and glycolytic potential (sum of total glucose and lactic acid content, given as lactate) in M. pectoralis major of modern broilers chickens. A total of 154 post-rigor breast muscle samples of male broilers of hybrid Ross 308 were used in this study. Broilers were divided randomly into three groups (A-C). Group A birds were not subjected to any exercise during the experiment. Group B birds lived 25 days exactly like group A but after that the drinking water dispensers was elevated to a higher level. Group C birds had their drinking water dispensers elevated to a 5 cm higher level after three days, and it was risen stepwise to 25 cm during the study. Broilers were slaughtered randomly from different groups at 20, 30 or 41 days old. Group B results were disregarded due to technical problems. Initial and ultimate pH, total glucose, free and in glycogen, and lactic acid contents for glycolytic potential, were determined from the breast muscle samples. The results showed that there were no differences between groups A and C (p > 0.05). There were differences between normal and WB cases in ultimate pH (pHu; p = 0.000), total glucose content (p = 0.000), lactate content (p = 0.007) and glycolytic potential (p = 0.000), but the pH values 5 minutes after death showed no significance (pH5; p = 0.190). There were differences in pHu, total glucose and glycolytic potential (p = 0.000), and lactate (p = 0.007), between ages 20, 30 and 41 days old birds. As the severity of WB increased in the breast muscle, the pHu increased and total glucose, lactate content and glycolytic potential decreased. The correlations showed significant relationships between WB score and all the above variables (p < 0.000). The results of the current study show that exercise does not have an effect on the levels of carbohydrates in M. pectoralis major of modern broiler chickens, but WB status and increasing slaughter age result a decrease in glycolytic potential and increase in ultimate pH.
  • Peltokangas, Kenneth (Helsingfors universitet, 2016)
    Loppijärvi on Kanta-Hämeessä sijaitseva matala humusjärvi, jonka rehevöityminen on edennyt poikkeuksellisen nopeasti viimeisen kymmenen vuoden aikana. Useista hoito- ja kunnostustoimista huolimatta järven rehevöityminen on jatkunut voimakkaana ja tilannetta pidetään huolestuttavana. Järven veden laadussa tapahtuneista muutoksista vesikasvillisuudesta ja kalastosta on saatavilla paljon tutkittua tietoa. Sen sijaan järven pohjasedimentistä tiedetään hyvin vähän. Tämän pro gradu -tutkielman tavoitteena oli kartoittaa järven pohjasedimentin tilaa, luoda yleiskuva järven rehevöitymiseen vaikuttavista fysikaalis-kemiallisista ominaisuuksista sekä arvioida sedimentin kuormituspotentiaaliin vaikuttavien ilmiöiden merkitystä. Tutkimus koostui kahdesta osasta. Ensimmäisessä tutkittiin järven pohjasedimentin ominaisuuksia järven eri osista otettujen sedimenttinäytteiden ja niistä määritettyjen raudan, alumiinin, kalsiumin ja fosforin kokonaispitoisuuksien avulla. Toinen osa koostui muhituskokeesta, jossa tarkasteltiin sedimentin happitilan ja järvikunnostuksessa yleisesti käytetyn alumiinikloridin vaikutuksia sedimentin sisältämän fosforin pidättymiseen ja jakautumiseen sekä arvioitiin sen soveltumista järvikunnostukseen laboratoriomittakaavassa. Sedimenttitutkimuksen perusteella Loppijärven nykyinen rehevöitymiskehitys johtuu sisäisestä kuormituksesta, eikä järveen kohdistu kuormitusta pistemäisistä lähteitä. Loppijärven sedimentin Fe:P-suhde vaihteli välillä 15–30. Sedimentin fosforipitoisuus oli noin 2,1 g P kg-1 koko sedimenttiprofiilin syvyydellä ja Fe:P-suhteen vaihtelu johtui pääasiassa sedimentin rautapitoisuudesta. Tulosten perusteella sedimentin fosforinpidätyskyky ei vastannut Fe:Psuhdetta, mikä viittaa muiden tekijöiden vaikuttavan raudan kykyyn pidättää fosforia. Muhituskokeen perusteella alumiinikloridikäsittely ei soveltunut sitomaan fosforia alumiinin aiheuttaman happamoitumisen takia. Alumiinikloridikäsittelyn vaikutus fosforin käyttäytymiseen vaihteli näytteiden hapetustilasta riippuen. Tulosten perusteella rauta sääteli fosforin vapautumista sedimentistä ja paras tulos kunnostustavoitteiden kannalta saatiin hapellisissa olosuhteissa ilman alumiinikloridikäsittelyä. Sedimenttitutkimuksen perusteella kemikaalikäsittelyt voivat auttaa kunnostustavoitteiden saavuttamisessa, mutta rehevöitymisen pysäyttäminen vaatii toimenpiteitä, jotka vaikuttavat sedimentissä vallitseviin olosuhteisiin tai sisäistä kuormitusta sääteleviin prosesseihin.
  • Laine, Anna M.; Lindholm, Tapio; Nilsson, Mats; Kutznetsov, Oleg; Jassey, Vincent E. J.; Tuittila, Eeva-Stiina (John Wiley & Sons Ltd, 2021)
    Journal of Ecology 109, 4 (2021), 1774–1789
    1. Most of the carbon accumulated into peatlands is derived from Sphagnum mosses. During peatland development, the relative share of vascular plants and Sphagnum mosses in the plant community changes, which impacts ecosystem functions. Little is known on the successional development of functional plant traits or functional diversity in peatlands, although this could be a key for understanding the mechanisms behind peatland resistance to climate change. Here we aim to assess how functionality of successive plant communities change along the autogenic peatland development and the associated environmental gradients, namely peat thickness and pH, and to determine whether trait trade-offs during peatland succession are analogous between vascular plant and moss communities. 2. We collected plant community and trait data on successional peatland gradients from post-glacial rebound areas in coastal Finland, Sweden and Russia, altogether from 47 peatlands. This allowed us to analyse the changes in community-weighted mean trait values and functional diversity (diversity of traits) during peatland development. 3. Our results show comparative trait trade-offs from acquisitive species to conservative species in both vascular plant and Sphagnum moss communities during peatland development. However, mosses had higher resistance to environmental change than vascular plant communities. This was seen in the larger proportion of intraspecific trait variation than species turnover in moss traits, while the proportions were opposite for vascular plants. Similarly, the functional diversity of Sphagnum communities increased during the peatland development, while the opposite occurred for vascular plants. Most of the measured traits showed a phylogenetic signal. More so, the species common to old successional stages, namely Ericacae and Sphagna from subgroup Acutifolia were detected as most similar to their phylogenetic neighbours. 4. Synthesis. During peatland development, vegetation succession leads to the dominance of conservative plant species accustomed to high stress. At the same time, the autogenic succession and ecological engineering of Sphagna leads to higher functional diversity and intraspecific variability, which together indicate higher resistance towards environmental perturbations.
  • Peuranen, Seppo (University of Helsinki, 1996)
  • Ylänen, Joanna (Helsingin yliopisto, 2020)
    Research of natural dyes and more ecofriendly textile materials has been of common interest for years. Research of natural dyes has mostly focused on the dyeing of wool, cotton, silk and regenerated cellulosic fibers. This study expands on this topic by combining natural dyes with the latest regenerated cellulosic fiber Ioncell®. When starting this study there was no previous research about the dyeing of Ioncell® and the most recently published research had only fo-cused on industrial dyes. By varying mordant type, acidity and colorant type, their respective effect on the fiber dye up-take could be studied. The data consisted of color measurements of the dyed samples, which were used to analyze the fiber dye uptake. The mordants used were alum, ferrous sulfate and tannic acid with unmordanted reference samples. Acidities used for the dye baths were pH 4 and pH 8. The colorants were dried skins of yellow onions [Allium cepa] and Cortinarius semisanguineus. Wool was used as a reference material for Ioncell® due to its color taking properties being well known and therefore, the dyeing process could be easily verified by it. A spectrophotometer was used for the color measurements. The color uptaking was evaluated by observing the color of the dyed samples and the differences in color between the undyed and dyed fibers. The color fastness to laundering as well as to artificial light were evaluated according to the standards SFS-ENG ISO-B02 and SFS-ENG ISO-C06 by assessing the col-or change, and fastness to laundering was also assessed by the staining of the multifiber ad-jacent fabrics. For a cellulosic fiber, Ioncell's® color uptake was low in alkaline dye baths. With Cortinarius semisanguineus as the colorant, the color take was low regardless of the acidity and the mor-dant type. With Allium cepa as the colorant, in the acid dye bath the color take was quite good. The color varied depending on the mordant used. However, these strong colors had lower color fastness to laundering than the pale colored samples. During staining differences occurred on the behalf of Allium cepa. Acidity or mordant only had an effect on the staining with alum mordanted samples dyed with Cortinarius semisanguineus. The best color fastness to light had alum and iron mordanted samples dyed with Allium cepa. With the tannin and iron mordants the acidity correlated with the color fastness to light, higher pH giving better results. During staining acidity or mordant only had an effect on alum mordanted samples dyed with Cortinarius semisanguineus. For further studies it would be interesting to see if the surprising results between flavonoid and anthraquinoine could be repeated with other dye source mate-rial and would the color uptake improve with the sodium pretreatment of Ioncell® fibers.
  • Pulli, Laura (Helsingfors universitet, 2017)
    Sinkki on raskasmetalli sekä tärkeä hivenaine ja mikroravinne. Maaperässä on sinkkiä n. 50 mg/kg. Sinkkiä on savimineraaleissa isomorfisen korvautumisen seurauksena. Kasveille käyttökelpoisen, liukoisen sinkin määrä suomalaisessa maassa on keskimäärin 5 mg/kg. Mineraaleista sinkki vapautuu maaveteen rapautumalla Zn2+-kationina. Sinkki on kasveille käyttökelpoisimmassa, liukoisessa muodossa, happamassa maassa. Maan pH:n noustessa liukoisuus vähenee ja sitoutuminen kationinvaihtopaikoille sekä oksidipinnoille voimistuu. Kasveilla sinkin puutosta voikin esiintyä kalkkimailla, tai voimakkaasti kalkitussa maassa, jossa on korkea pH. Sinkki sitoutuu sekä epäspesifisesti kationinvaihdolla, että spesifisesti ligandin vaihdolla. Korkea pH edesauttaa kumpaakin sitoutumismekanismia. Suomessa kasvien sinkkipitoisuus on suurimmaksi osaksi tyydyttävä tai hyvä. Tässä tutkimuksessa tarkasteltiin maan ominaisuuksien merkitystä lisätyn sinkin liukoisuuteen maassa. Maanäytteitä oli 59 kpl ja ne olivat kivennäismaita eri puolelta Suomea. Näytteet olivat muokkauskerroksesta viljelyssä olevilta pelloilta vuosilta 1987 ja 1989. Maanäytteille oli tehty muhituskoe sekä astiakoe. Maanäytteet oli fraktioitu peräkkäisten uuttojen menetelmällä sekä yksittäisillä uutoilla. Muhituskokeiden sekä astiakokeiden tuloksista tehtiin regressioanalyysejä sekä parittaisia t-testejä. Regressioanalyyseillä tutkittiin kuinka maan eri ominaisuudet selittävät sinkin liukoisuutta maassa tai kasvin sinkkipitoisuutta sekä sinkin ottoa. Tässä työssä tulokset osoittivat pH:n olevan tärkein tekijä sinkin maaperä-käyttäytymisessä. Sinkki on liukoisimmillaan happamassa maassa. Lisätyllä sinkillä oli merkitystä kasvin sinkkipitoisuuteen, mutta ei satoon. Sinkkilannoitus kannattaa alhaisen pH:n maissa, mutta ei korkean pH:n maissa. Maan ominaisuuksien merkitys sinkin sitoutumiseen on tärkeä tuntea, jotta lannoituksella ei lisätä vain maan sinkkipitoisuutta.
  • Westman, Carl Johan (Suomen metsätieteellinen seura, 1990)
  • Lehto, Anne-Mari (Helsingin yliopisto, 2019)
    Tiivistelmä gradun pdf-tiedostossa.
  • Kejzar, Nejc (Helsingin yliopisto, 2020)
    AMPA receptors (AMPARs) are the most numerous synaptic receptors in the hippocampus. Here they take one of the central roles in the expression of long-term potentiation (LTP), the molecular mechanism underlying learning and memory. They belong to the group of glutamate-gated ion channels and have a structure characterized by 4 discrete domains. While the functional roles of C-terminal (CTD), transmembrane (TMD) and ligand-binding (LBD) domains have largely been established, the regulatory capacity - if any - of the N-terminal domain (NTD) remains questionable. In this thesis we used molecular dynamics (MD) simulations to show directly for the first time that AMPA receptor NTD domain can respond to the pH of the surrounding medium. Specifically, we identified a pair of histidine residues in the NTD interface, which are capable of acting as pH sensors - upon acidification of the environment the two histidines become protonated and through electrostatic repulsion destabilize the NTD interface. If experimentally validated, this model could provide a mechanistic explanation of AMPAR clustering in synapses. Due to low affinity for glutamate under physiological conditions, it has been proposed that AMPARs form clusters right underneath glutamate release sites in order to produce sufficiently large postsynaptic depolarizations. Since the lumen of glutamate vesicles is acidic, the presynaptic glutamate release is coupled to transient acidification of the synaptic environment. In our model this acidification is detected by identified interface histidines, which upon protonation cause structural rearrangement of the NTD interface. This rearrangement could lead to formation of interactions either with other AMPARs or synaptic anchor proteins (such as PSD-95), resulting in AMPAR clustering underneath glutamate release sites.
  • Wang, Shiqi (2021)
    The intracellular delivery of emerging biomacromolecular therapeutics, such as genes, peptides, and proteins, remains a great challenge. Unlike small hydrophobic drugs, these biotherapeutics are impermeable to the cell membrane, thus relying on the endocytic pathways for cell entry. After endocytosis, they are entrapped in the endosomes and finally degraded in lysosomes. To overcome these barriers, many carriers have been developed to facilitate the endosomal escape of these biomacromolecules. This mini-review focuses on the development of anionic pH-responsive amphiphilic carboxylate polymers for endosomal escape applications, including the design and synthesis of these polymers, the mechanistic insights of their endosomal escape capability, the challenges in the field, and future opportunities.